# n'avait pas dû le voir venir



## kategogogo

_Le surveillant venait d'ouvrir la porte et Joachim *n'avait pas dû* le voir venir._

Hello, forum. It is a quote from Le petit Nicholas. The scene is the boys were having a catching in the classroom, suddenly Joachim saw the supervisor Bouillon come back and heard him open the door. Should I translate "n'avait pas *dû*" as "*must *not have seen (him come back)"?


----------



## OLN

Bonjour kategogogo.
_
Venir =_ _come_, pas _come back_ (_revenir_), mais le reste semble être une question de grammaire.
_
- must not have seen _serait plutôt _n'a pas dû voir_ (passé composé)_. 
- n'*avait *pas dû_ _voir _est au *plus-que-parfait* car l'action est antérieure à _venait d'ouvrir.
_
Je pensais qu'avec "must [not] have",  la concordance des temps n'était pas respectée, mais apparemment,_ must have + p.p_ rend correctement le plus-que-parfait français.
Cf. FR: could have / should have / would have / must have / might have (n°4 ; j'ai rajouté la couleur)


geostan said:


> I must have gone to the movies is often translated by the passé composé, but note that as a clause in indirect speech dependant on an introductory verb in the past, it would be translated by the pluperfect, e.g.
> 
> I told him that they must have gone to the movies. Je lui ai dit qu'ils avaient dû aller au cinéma.



Suggestion :_ ...had just open the door and Joachim probably *had* not seen him coming _(pluperfect)

Le livre n'est-il pas déjà traduit en anglais ?


----------



## Hildy1

kategogogo said:


> Should I translate "n'avait pas dû" as "must not have seen (him come back)"?



That is a good way to translate it.


----------



## kategogogo

Merci pour votre aide OLN et Hildy1. J'ai pas ce livre en anglais à portée de main. Par ailleurs, je crois que ce forum m’aide mieux que celui du version anglaise.


----------



## Enquiring Mind

In addition to "mustn't have seen," you could have "can't have seen" or "couldn't have seen" here.


----------



## JClaudeK

Enquiring Mind said:


> In addition to "mustn't have seen," you could have "can't have seen" or "couldn't have seen" here.



This would change the meaning, wouldn't it?
cf.: 


OLN said:


> ...had just open the door and Joachim *probably* had not seen him coming


----------



## Enquiring Mind

Hello JCK, no, it doesn't change the meaning. We are talking about the *probability* sense of "devoir".
_
Le surveillant venait d'ouvrir la porte et Joachim *n'avait pas dû* le voir venir. _The narrator is drawing the conclusion that Joachim didn't see the_ surveillant_ coming, or, as OLN said, 





> ..had just opened the door and Joachim *probably* had not seen him coming


_Joachim can't have seen him coming _or _Joachim couldn't have seem him coming _are both ok (and better than "mustn't have"). OLN's suggestion in #2 _probably had not seen him coming _is fine, as well, as is _Joachim probably didn't see him coming_. Don't get too hung up on the sequence of tenses. Joachim "seeing him coming" couldn't happen before the surveillant opened the door (unless Joachim could see through the door/wall), so the (English) tense shifts are not a description in time of what happened, they are due to the "reported speech" requirement.

"Can't" is okay because even at the time of the narration, the deduction that Joachim probably didn't see him coming is still true.

_Joachim *n'avait pas dû* le voir venir = _"mustn't have" is okay, but is beginning to sound dated, even in BE these days, and AE speakers, in particular, will tend not to use this "mustn't have + past participle to express probability" construction.

[I wonder if this should be in Grammar rather than Vocab?]


----------



## JClaudeK

Thanks for your explanations, EM.


----------



## Reynald

I'm as puzzled as JCK (# 6 ) that you chose _can_ instead of _must_. To me :
- mustn't have seen him coming = n'avait pas *dû* le voir venir (probability).
- couldn't have seen him coming = n'avait pas *pu* le voir venir (materially impossible for him to see him coming - because of someone standing between him and the door, for example - or simply = ne l'avait pas vu venir / _can_ avec les verbes de perception).

It's your choice of the verb that I don't understand, not the sequence of tenses. Because it does change the meaning of the French sentence.


----------



## JClaudeK

Reynald said:


> It's your choice of the verb that I don't understand, not the sequence of tenses.


C'est de ça que je parle, moi aussi !


----------



## Enquiring Mind

Hello chaps: please see these threads: Cela n'a pas dû être facile, can't/must not/didn't have to have done something, and many more here, in particular this one: can't or mustn't, where carolineR is absolutely spot on, especially in her post 27, where she takes to task those pesky school inspectors (who are wrong):


> and *you would actually say* a sentence like "Alice mustn't have been killed in the car accident" ? I mean it *is* used ???
> the reason I am insisting is
> 1. in 50 years of studying English, I don't think I've ever heard/read it,
> 2. it is the latest craze among inspectors in France : one mustn't teach can't is the opposite of must (epistemic use, of course), one must teach mustn't...


The choice of verb is clouded by the fact that there is an overlap in meaning and usage (both in French and English) between _n'a pas pu _and_ n'a pas dû _(in the _*negative probability*_ sense)_._
What did McEnroe say to the umpire? "You cannot be serious!" - "vous ne pouvez pas être sérieux!" = "vous n'êtes sûrement pas sérieux!". He certainly was not saying "vous n'êtes pas capable d'être sérieux!", so pouvoir can also have this _probability _or_ logical deduction_ meaning.
And what about this little girl ["I'm watering a shoe.  Fuck off!"] - she mustn't/can't have been taught good manners - elle _n'a pas dû_ être .... (yes, I know there are better ways of saying this, but it's the "devoir" sense I'm bringing out here).

So in kategogogo's context, Joachim _ *n'avait pas dû = *_*evidently hadn't seen* (*mustn't/can't/couldn't have seen*) the _surveillant. _I personally don't use "mustn't" here. As I said earlier and as some of the posts in the linked threads confirm, it is already sounding dated in BE (and risks confusion with the "obligation", rather than "probability" sense of "mustn't"), and many AE speakers don't use it in this negative probability sense.

And see the relevant Reverso examples here.


----------



## kategogogo

Very instructive, Enquiring Mind. Similarly, "must have + past participle" is also a dated way to express probability, I reckon? If the sentence was "_Le surveillant venait d'ouvrir la porte et Joachim *avait dû* le voir venir_", "Joachim *could have *seen him coming" would be the optional choice, rather than "Joachim _*must have *_seen him coming"?


----------



## Enquiring Mind

Aye, there's the rub (well that's the problem), kategogogo. In the *positive probability* sense, "must have" is absolutely fine, not dated at all.
_Joachim *avait dû* le voir venir - Joachim must have see him coming . Could have seen _here, in the positive sense, would be something else. It is physical possibility or positive assumption, and would probably be "aurait pu".

It's (only) in the *negative probability* sense that this problem arises.

Logical deduction/probability/(near-)certainty:
Positive: must have
Negative: can't have, couldn't have (mustn't have)

More here: (pearsonlongman.com) and here:


> I don't understand when and why to use *can't have been*. It seems so strange to me.
> You *can't have been* paying attention when your English teacher covered this!
> (...)
> This is because* the epistemic sense of can is a negative polarity item,
> and requires a negative trigger.* Without a negative, you can't use _can_ epistemically.(english.stackexchange.com)


----------



## Reynald

Enquiring Mind said:


> Logical deduction/probability/(near-)certainty:
> Positive: must have
> Negative: can't have, couldn't have (mustn't have)


Thanks for the detailed explanations and the links E.M. Now, that's clear and this little summary above is easy to remember.

Just one more question: Apart from the "dated usage" question, isn't the probability stronger when you use _can't _in the negative than when you use _must not / mustn't?_ 
Or is it perfectly equivalent?


----------



## Enquiring Mind

According to this poster, errm - 4% . 


> Sam *can't have been * hungry. (The speaker believes - is 99% certain -that it is impossible for Sam to have been hungry.)
> Sam *must not have been* hungry. (The speaker is making a logical conclusion. We can say he's about 95% certain.) (pearsonlongman.com)


Well, you *did* ask!
That poster may be a better mathematician than me, but to be serious, I think it's much of a muchness, six of one and half a dozen of the other, it makes no odds. The sense of the level of certainty probably isn't conveyed solely by which verb you choose.


----------



## Reynald

_More _or_ less _certain would have been enough_, _but thanks for the link. Fascinating!


----------



## sound shift

The meaning of _mustn't have + past participle_, _can't have + p.p._ and _couldn't have + p.p._ is affected by the fact that some people don't use all three. I, for example, don't use _mustn't have + p.p._, but I use the other two. Consequently, if I say "Sam can't have been hungry", the guidance about percentages of certainty in the extract from pearsonlongman.com quoted in post 15 doesn't apply to me. There are regional factors at work. For example, many in the North of England use _mustn't have + p.p., while can't have + p.p. _seems not to be part of the usage of some of the North American members of this forum, to judge from other threads.


----------



## JClaudeK

Enquiring Mind said:


> So in kategogogo's context, Joachim _ *n'avait pas dû = *_*evidently  hadn't seen* (*mustn't/can't/couldn't have seen*) the _surveillant.
> [....]_
> about 95% certain
> [....]
> It's (only) in the negative probability sense that this problem arises.
> Logical deduction/probability/(near-)certainty :


C'est là que réside le problème:
Joachim _ *n'avait pas dû voir = *_*evidently hadn't seen  => probably hadn't seen *
 Visiblement, tu interprètes mal la tournure française "il n'a pas dû ..... "* !

"Il n'avait pas dû voir =* il n'avait sans doute pas vu *"* = est une *supposition*, pas une (quasi)certitude !


----------



## Enquiring Mind

Well, I would actually say "can't have seen", JCK, as I said in posts 5 (et seq.), but there's nothing wrong with "evidently" here in the way I used it. 


> *evidently*
> adverb UK  /ˈevɪdəntli/ US
> OBVIOUSLY: used to say that something can easily be noticed.
> (...) _He evidently likes her._
> PROBABLY: seems probable from the information you have
> (...) _The intruder evidently got in through an open window._(cambridge.org)


And see the relevant "n'a pas dû" Reverso examples here.


----------



## Hildy1

JClaudeK said:


> C'est là que réside le problème:
> Joachim _ *n'avait pas dû voir = *_*evidently hadn't seen  => probably hadn't seen *
> Visiblement, tu interprètes mal la tournure française "il n'a pas dû ..... "* !
> 
> "Il n'avait pas dû voir =* il n'avait sans doute pas vu *"* = est une *supposition*, pas une (quasi)certitude !



Evidently, EnquiringMind was using "evidently" in this sense:

to all appearances; apparently: they are evidently related
evidently - WordReference.com Dictionary of English

sentence adverb 
It would seem that.
_‘evidently Mrs Smith thought differently’_
evidently - definition of evidently in English | Oxford Dictionaries


----------



## JClaudeK

Enquiring Mind said:


> And see the relevant "n'a pas dû" Reverso examples here.


And see the relevant (?) "could not have been" Reverso examples here.


----------



## Enquiring Mind

Yes, of course. I'm not arguing that can = devoir. Those examples are taking us down a blind alley.

The issue here is whether "n'avait pas dû voir" (in the negative probability sense) can be translated as "can't have seen", and many of the Reverso examples for "n'a pas dû" offer "can't have". Judgements about what degree of certainty is conveyed by "can't have" (in the negative probability sense) are subjective, and each example needs to be looked at in its context. For me _Le surveillant venait d'ouvrir la porte et Joachim *n'avait pas dû* le voir venir _can be rendered as "can't/couldn't have", and the meaning is pretty much synonymous with "probably hadn't".

It could be that some are not appreciating the distinction between the "ability" and "*prob*ability" senses of "can't".


----------



## Reynald

Je n'avais jamais vraiment fait attention à cette possibilité (négatif _can_ = ne doit pas).
Pour une explication en français, elle se trouve dans la _Grammaire explicative de l'anglais_ de Paul Larreya et Claude Rivière : 8.1.5. a p.96. Extrait (mais tout le chapitre est vraiment intéressant et complet sur le sujet) :


> En anglais britannique, on utilise fréquemment _cannot / can't_ (et non_ must not_) ) pour exprimer le caractère fortement probable d'un fait négatif : l'équivalent de "Il ne doit pas être chez lui à cette heure-ci" sera _He can't be  at home at this time of day_. Autre exemple ; _"You can't be serious"_ (Dan Brown, _The Da Vinci Code_).



Voir aussi les cas où ce n'est pas possible (le chapitre entier s'affiche).


----------



## Enquiring Mind

Thank you for checking this out, Reynald. Unfortunately the chapter is not visible to me in the preview version, but I think they have put their finger on the distinction there in the extract you quoted. Whether negative-probability "il n'avait pas dû" in French expresses something that is "fortement probable" or just "probable" is probably (or very probably? ) a matter of subjective interpretation too.


----------



## JClaudeK

Normalement, je ne voulais pas revenir à la charge, mais je suis tombé sur ce passage dans le livre _Recherches en linguistique étrangère, XIX: mélanges Jean Tournier, Volume 19_
passage dont je ne veux pas vous priver.


> Les ouvrages de grammaire présentent souvent _cannot_/_can't_ comme un substitut possible de _must not_ pour l'anglais britannique, mais ceci n'est pas tout à fait exact, [...] en premier lieu parce que le degré de probabilité exprimé par _ cannot et must not _n'est pas tout à fait le même.


----------



## Enquiring Mind

Thanks JCK. Alas Prof. Larreya's sentence occurs at the end of that section of the text, and he doesn't develop the idea or give examples to show what he means so we are not really much the wiser, and as we've already mentioned in this thread, judgements about degrees of probability are subjective. If the difference of probability (between "can't have been" and "mustn't have been") is 4% (according to the link in #15), it's negligible. Also, that sentence is tacked on to the end of a section dealing with the difference in probability between "must" and "have to", which is the "duty" sense of "must", not the "negative-probability" sense.

But as some of the previously linked threads and my posts have mentioned, many BE and AE speakers don't use negative-probability "mustn't have" _*at all*_ as it's becoming dated (or regional dialect); I don't, sound shift (#17) doesn't, many posters on the linked threads in the English-only forum say they don't, so for these people "mustn't have" doesn't exist at all as an option in active usage. For us, there is no relevant concept of a difference in the degree of probability (even if it's only 4%), because there is only one option - can't/couldn't have, and no "mustn't have" for comparison.


----------



## Genarti

Enquiring Mind said:


> But as some of the previously linked threads and my posts have mentioned, many BE and AE speakers don't use negative-probability "mustn't have" _*at all*_ as it's becoming dated (or regional dialect); I don't, sound shift (#17) doesn't, many posters on the linked threads in the English-only forum say they don't, so for these people "mustn't have" doesn't exist at all as an option in active usage. For us, there is no relevant concept of a difference in the degree of probability (even if it's only 4%), because there is only one option - can't/couldn't have, and no "mustn't have" for comparison.



For what it's worth, as an AE speaker, I wouldn't likely say "mustn't have" -- but I would, and frequently do, say "must not have."  It's the contraction that makes it sound old-fashioned or British to my ears (though clearly it's not necessarily used by BE speakers either), but without the contraction it's a perfectly common usage in my region.  "Joachim must not have seen him come back" sounds perfectly reasonable to me.


----------



## Enquiring Mind

Can you suggest how strong the probability of "must not have seen him come back" sounds to you, Genarti? "He almost certainly didn't see him come back", "he probably didn't see him come back", or something else? I know this is a bit of a daft question since we're dealing with a single sentence out of context, and the sense of probability may well be further refined by other context...


----------



## Genarti

Enquiring Mind said:


> Can you suggest how strong the probability of "must not have seen him come back" sounds to you, Genarti?



It sounds to me like a subjective conclusion, but a pretty confident one.  Someone stating a conclusion with a fair degree of certainty.

In order from most certainty to least certainty, I'd say:

- He must not have seen him come back  (statement of a conclusion one is personally quite sure of)
- He couldn't have seen him come back  (statement of a conclusion, very slightly less certain to my ears, but contains a little ambiguity because it could also be a very certain statement of facts: "He (physically) couldn't have seen him come back, because there was a wall in the way.")
- He can't have seen him come back  (statement of a conclusion, but to my ear has a little bit of implied uncertainty to it.  An implied, "he can't have seen him come back, or he'd have said something... right?")
- He probably didn't see him come back   (less certain: "he probably didn't, but maybe he did")


----------



## Enquiring Mind

Thanks, that's really interesting. Earlier in this thread (#2, 9, 18) our French-speaker foreros were at pains to point out that "n'avait pas dû" means "probably" and the suggestion was made in #9





> - mustn't have seen him coming = n'avait pas *dû* le voir venir (probability).


and in #18 





> *"Il n'avait pas dû voir =* il n'avait sans doute pas vu *"* = est une *supposition*, pas une (quasi)certitude !


but your opinion as an AE native speaker (which I would agree with in BE usage too - where it exists) is that 





> - He must not have seen him come back (statement of a conclusion one is personally quite sure of.)


  That, indeed, is why I have been claiming that "mustn't have" ("a conclusion one is personally quite sure of") is not good in kategogogo's context for "n'avait pas dû" (probably hadn't) and, in my usage (because I don't use negative-probability "mustn't have"), is "can't/couldn't have" which, here, is not "n'avait pas pu".


----------



## pointvirgule

OK, let's go back to the context. That day, the teacher is absent, so for a while the class is left without any adult supervision. The pupils decide to play ball and Joachim is given the task of being the lookout, watching through the keyhole the arrival of the "surveillant" (Eng?), nicknamed "Bouillon." At this point,


> Et puis, on a entendu un cri et on a vu Joachim assis par terre et qui se tenait le nez avec les mains. C’était le Bouillon qui venait d’ouvrir la porte et Joachim n’avait pas dû le voir venir.


So, the narrator didn't see what happened but makes a logical assumption after the fact. I think we could simply say, _I guess he didn't see him coming_.

About _can't/couldn't have seen_ (#5): I'm sorry to be sorry, but in the context, that would suggest to me that it was _impossible _for Joachim to see Bouillon coming (as Reynald already remarked in #9), which is not the case. Hope this helps.


----------



## Enquiring Mind

Thanks pv, this is the precise point at issue here. To me in that context, it doesn't mean "impossible". Joachim wasn't blind and he was on the lookout through the keyhole. It was his job to see Bouillon coming. It means (as you say) "I guess he didn't see him", or (as I said) "he evidently didn't see him". The narrator is concluding that Joachim *didn't* see him, not that he couldn't see him or that it was impossible for Joachim to see him.
So the narrator's conclusion is that Joachim can't have seen him = the likelihood is that he didn't see him. (*Prob*ability, not ability.)

The Merriam-Webster entry for "can" here says


> "e :  be made possible or probable by circumstances to,
> he _can _hardly have meant that.


My contention is that the meaning of "can" in "can't have seen" is "be made probable by circumstances"; others only seem to allow the meaning "be made possible". The opposite of "can" is "can't" - so "be made improbable". Joachim can't have seen him coming. It is improbable that Joachim saw him coming. Joachim probably didn't see him coming - il n'a pas dû.


----------



## Nicomon

About _can't / cannot_, this is what follows the extract that Reynald quoted in post 23:  





> Cet emploi de _cannot / can't_, toutefois, est soumis à certaines restrictions : il ne faut pas traduire systématiquement le français « il ne doit pas… »  (sens de forte probabilité) par _ he can’t…  _On peut donner la règle pratique suivante : il est impossible d'utiliser _he can't_... comme équivalent de « il ne doit pas… » dans les cas où (en français) le remplacement de « il ne doit pas… » par « il ne peut pas … » est impossible. Ainsi, « Regarde, il s'en va, il ne doit pas aimer le film » se traduira par _Look, he's leaving, he probably doesn't like the film_, et non par ... _he can't like the film._


  The meaning in French wouldn't be the same if the author had written  :  _ Il n'avait pas *pu* le voir venir.  _
Whereas  _You can't be serious_ could be translated as _Tu ne dois pas être sérieux / Ça ne se peut pas que tu sois sérieux._

This is the way I would understand the given suggestions, from English to French.
_
- Can't have seen / couldn't have seen him coming =_ _ne peut pas l'avoir vu / n'aurait pas pu le voir venir. 
- Joachim must not have seen him coming =  Joachim n'a pas dû le voir venir. _(even after reading OLN's quote of geostan's reply, from another thread_) 
- Joachim probably didn't see him coming =  Joachim ne l'a sans doute / probablement pas vu venir. 
- I guess he didn't see him coming = Je suppose qu'il ne l'a pas vu venir.

N'avait pas dû le voir venir = ne l'avait sans doute pas vu = je suppose qu'il ne l'avait pas vu. _
OLN's suggestion, right from start in post 2, sounds right to my francophone ears...
And I like pv's rendering with  "_I guess_" but don't understand why he used the simple past "_didn't see_".

How do you make the difference between passé composé and plus que parfait?
Would it be right to say :  _ I guess he had not seen him coming?  _ And if not, why?  I'm seriously asking for my own knowledge.

Le plus que parfait (entre autres difficultés) me cause toujours problème, quand vient le temps de traduire vers l'anglais.


----------



## Enquiring Mind

Thanks Nico,


> How do you make the difference between passé composé and plus que parfait?
> Would it be right to say : _I guess he had not seen him coming? _


 Yes, that's certainly an option for me, but unnecessarily clunky when "I guess he didn't see him coming" has the same meaning (as does "he can't have seen him coming" with the probability element of "I guess" rendered by the probability meaning of "he can't have ...").

I'll just point out another reference to this negative-probability "can't have" usage: (Fiches et tests de grammaire, Fiche 19, page 71)(Claude Rivière)


> 4. CAN *(A) Modalité de phrase* [uniquement avec la négation ou dans les questions], une forte probabilité négative [voir _*MUST*_ A]
> _He can't have seen the traffic lights. _Il n'a pas dû voir les feux. _(...) _Cet emploi de CAN'T correspond en français aussi bien à _ne peut pas_ qu'à _ne doit pas_.
> (...)
> *fortes chances que non*
> _Jim can't have read that book_
> Jim n'a pas dû lire ce livre


----------



## Reynald

On remarque aussi qu'à chaque fois les auteurs précisent "en anglais britannique". L'usage américain de _must not_ dans ce cas (Hildy1, #3 et Genarti, #27) semble moins rare.  

Dans leur Grammaire anglaise de l'étudiant, Berland-Delépine et Butler traitent aussi la question :


> 88. _*Forte probabilité, quasi-certitude, conclusion logique*_
> Dans ce sens _must_ s'emploie surtout à la forme affirmative. Le contraire de *"that must be true"* est généralement *"that can't be true"* en anglais britannique.


Puis, pour un exemple de _must not_ exprimant une quasi-certitude, les auteurs donnent une citation d'un auteur américain.


----------



## Nicomon

Thank you EM. I just noticed what you wrote in post 7  : 





> Don't get too hung up on the sequence of tenses. Joachim "seeing him coming" couldn't happen before the surveillant opened the door.


 The way I understand the French sentence, it could.  It's not "coming in".  _Venir_ more or less means _approaching_.

It's clear  that the English doesnt work the same way, but in French it would sound very odd / wrong to use  « passé composé _» _after « imparfait _»_:
_Le surveillant *venait *d'ouvrir la porte et Joachim *n'avait pas dû* le voir venir. 
Le surveillant *venait *d'ouvrir la porte et Joachim *n'a pas dû* le voir venir _By the way, your _can't have seen _translates this_, _as per your example from Claude Rivière...

Which is what raised my question.  I thought there was a difference to be made between _(probably/I guess he) didn't see_ and _(probably/I guess he) had not seen_.
So now I'm wondering when, if ever, _had not seen  _is used  or if it always sounds "clunky".

In any event, the francophone/non BE in me wants a clear way to distinguish between_ probable _and_ impossible / _between _dû_ and _pu_.  
So..._ can't have seen  _doesn't work for me in this context. I prefer, by far, _evidently hadn't seen, _as you wrote in post 11, where_ evidently _means _apparently. _

Go figure why  I have no issue at all with _that can't be true / you can't be serious.   _


----------



## Enquiring Mind

You make a fair point about the sequence of tenses now that the context has been clarified by PV in #31, Nico. From the context supplied in the original post 





> Joachim saw the supervisor Bouillon come back and heard him open the door...._Joachim *n'avait pas dû* le voir venir._


 the situation wasn't clear (to me), and especially it wasn't stated that J was looking through the keyhole for precisely this reason. Now that's clear, J obviously could have seen him coming before the door opened.

I agree too about _see him coming *in*, _or_ coming, _or _just come, _or_ even approaching, _as you note. These requests for translation of single sentences are always a bit of a pain in the posterior, because we cannot get a clear sense of the timeframe (especially in a past time narrative), which is often crucial to the choice of verb tenses and progressive/continuous forms, to the use of articles (though that's not an issue here), and other semantic elements.


> _Le surveillant _*venait *_d'ouvrir la porte et Joachim _*n'a pas dû*_ le voir venir._


I agree, too (gosh, it must be all those Easter eggs!), that this is not good in French, but I can't agree that "can't have seen" translates *only* this tense. We are in a narration (that's the key point) describing events in past time, and the narrator's sense of time* can* - in English - move all over the place from present to past simple, pesent perfect and pluperfect, and often does. Otherwise we would have continual successions of "had" and "had been" which would be clumsy. So for this very reason (if for no other), the English tense can change (when and where possible) to avoid this stylistic clumsiness - sometimes (apparently) regardless of the real sequence of events in time.

You can't have failed () to notice my sentence in post 7 





> "Can't" is okay because even at the time of the narration, the deduction that Joachim probably didn't see him coming is still true.


Let's use your "probably didn't/hadn't" scenario with the tenses as in the post we've been discussing here:
_the rocket had taken off from the launch site but the booster stages probably didn't ignite properly, and it exploded. _At the time of the narration, the deduction that the booster stages didn't ignite/hadn't ignited is still true. (At the time of the Joachim narration, the deduction that J didn't see/hadn't seen Bouillon is still true.) "Probably hadn't ignited properly" is ok too, of course, but clunkier. Enfin, pourquoi faire difficile quand on peut faire facile ?

The issue of "can't have noticed" versus "couldn't have noticed" in this negative-probability-in-the-past scenario is not necessarily tied to the sequence of time events of the action being described. These two *may* express *different degrees of probability* ("couldn't" is  - or may be, in the specific context - interpreted as less certain than "can't", as explained by Genarti in 29 and many of the linked posts on the English forum).

So these apparently "bizarre" shifts of tense in past time* narration* in English can cause great confusion to French speakers, because the tense sequences in French are much more precise. Indeed, many English natives' posts on this forum show this phenomenon, and - conversely - we rosbifs sometimes get the impression that French speakers are "too hung up" on the sequence of tenses in English. Again, it is not unusual to find on this very forum that (non-Cartesian apparently chaotic) English tense use is one of the bêtes noires for French speakers. We have more latitude in English than in French. 





> In any event, the francophone/non BE in me wants a clear way to distinguish between_ probably _and_ impossible / _between _dû_ and _pu_.


 The point I made in #11


> The choice of verb is clouded by the fact that there is an overlap in meaning and usage (both in French and English) between _n'a pas pu _and_ n'a pas dû _(in the _*negative probability*_ sense)_._


 is key here, I think. Difference between "devoir" and "pouvoir" - usually no problem, but it's specifically with this negative probability in the past that this issue (n'avait pas pu/n'avait pas dû -_ can't/couldn't/[mustn't] have_) arises. It is a (mostly nocturnal) grammatical rare species that feeds on the brain cells of (mostly nocturnal) Word Reference foreros. That is its unique habitat, and that is why we have had to delve deep into the undergrowth of rarely-visited grammar manuals to find it quietly minding its own business, watering a shoe (#11), and wishing we would just leave it in peace and get back to those ancient Egyptian mirrors. With this construction, we have travelled beyond the dimension of time or tense into the universe of *modality *, a universe where nothing is concrete, and everything is subject to personal interpretation. Alas, I fear there will be cases where the distinction between "n'avait pas pu" and "n'avait pas dû" will never be understood in the same way by everyone. This, indeed, is what this thread has shown.


----------



## Nicomon

I'm afraid I'll have to read this long post again and again,  for everything to sink in. 

In a nutshell, and as I wrote earlier,  I would associate "_couldn't have seen_ _him coming_" to « *n'aurait* _pas *pu* le voir venir_ »  and not  « _*n'avait* pas *dû* le voir venir_».
e.g.  (for me) :   _It couldn't have been worse_ = _Ça n'aurait pas pu être pire  /  You couldn't have said it better =  Tu n'aurais pas pu mieux le dire. 
_
It's really not easy for an old French Quebecer to learn to talk like a British native. 
So I think it's way past time for me for me to move to another thread._.. _ and perhaps stick to English to French translation.

Edit -   Incidentally, unlike _He can't have seen, _this bit : 





> You can't have failed () to notice


 is perfectly fine to my ears. It's in the same line as  _That can't be true / You can't be serious. 
_
To me, those are all closer to _certainly _as in_ : certainly that's not true / certainly you're not serious/ certainly you have noticed , haven't failed (didn't fail) to notice.

_


----------



## Enquiring Mind

Yes, for me too (your 2nd paragraph translations). But the author in Joachim's case did write "n'avait pas *dû* le voir venir" and the issue is how that is rendered in English. As I said in #32, many French speakers don't seem to allow for the Merriam-Webster "be made *probable*" sense of can here, which can be conveyed in the negative in the past by "can't/couldn't have" (negative probability). They seem to default automatically to the "be made *possible*" sense, or else suggest that "can" cannot render "devoir".


> CAN: be made possible or probable by circumstances to,
> he _can _hardly have meant that.


The grammar book quotes in #34 and #35 clearly show the construction. 





> _He can't have seen the traffic lights. _Il n'a pas dû voir les feux. _(...) _Cet emploi de CAN'T correspond en français aussi bien à _ne peut pas_ qu'à _ne doit pas_.



[Add:  "You can't have failed ... It's in the same line as _That can't be true / You can't be serious". _The construction we're discussing  (+ past participle) is specific to the sense of "can't have" in the context of negative probability in the past. Discussing it in the context of a present tense sense (can't be true) muddies the waters.]


----------



## Nicomon

I added an edit to my previous post, as you were writing this one.

I maintain (along with others who said it before me) that _n'avait pas dû  le voir = ne l'avait sans doute pas vu = je suppose _(mais n'en suis pas certaine) _qu'il ne l'avait pas vu. _
So it's either that I'm too stubborn to get the subtlety of the English "probable can't" or that you're missing the nuance in the French sentence.

_Can't have seen_ may be right after all, but I can't help it... to me, that doesn't work in context.
Again, I much prefer (as you also suggested) :  _He evidently / apparently hadn't seen_ _him coming_.  Or pv's : _I guess he didn't see him coming. 
_
Now, I'm *really* changing threads_.  _


----------



## Enquiring Mind

Not a question of me missing the nuance, I don't think (my mother was French). I assume Mr Rivière in post 34 understands the nuance, and he is happy with "can't have" for "dû".  So there are three options. The third is that some native French speakers refuse to believe what another native French speaker tells them.


----------



## Nicomon

My mistake.  I didn't know that your mother was French. 

Fourth option : If those native French Quebecers are given a choice of solutions... they don't choose the one they're less familiar with.


----------



## Reynald

Enquiring Mind said:


> With this construction, we have travelled beyond the dimension of time or tense into the universe of *modality *, a universe where nothing is concrete, and everything is subject to personal interpretation. Alas, I fear there will be cases where the distinction between "n'avait pas pu" and "n'avait pas dû" will never be understood in the same way by everyone. This, indeed, is what this thread has shown.


La faute au p'tit Nicolas ! Oui, les modaux peuvent être un casse-tête pour les Français.

S'il reste quelques masos sur ce fil, le cours de Paul Larreya sur le sujet (notamment à partir de 2.3.2.) est disponible à la lecture en ligne ici. Il y pointe notamment la différence entre l'usage britannique et l'usage américain. Également intéressante, la question de l'expression de la probabilité au futur, que nous n'avions pas envisagée , avec l'introduction de _is_ _bound to_.


> e. La forme négative _(He must not be at home)_ est utilisée en anglais américain, mais elle est généralement considérée comme incorrecte en anglais britannique "standard". (En anglais britannique, c'est donc la forme _He can't be at home_ qui sera normalement utilisée.) Notons qu'en anglais américain il existe donc deux formes (qui ne sont pas synonymes): _He must not be at home_ et _He can't be at home_.
> 
> 2. Expression d'une forte probabilité
> On peut toujours employer_ must_ (avec une restriction à la forme négative, voir plus haut), mais_ have to_ est également employé (notamment en anglais américain) pour exprimer une "très forte probabilité": _You've got to be joking!_ (Tu plaisantes, c'est pas possible!) / _There HAS to be a mistake somewhere! _(C'est obligé, il y a une erreur quelque part!)
> 
> a. Lorsqu'il est suivi d'une base verbale ou de _be + -ing_, _must_ exprime le caractère fortement probable d'un événement qui est généralement situé dans le présent; pour exprimer la forte probabilité d'un événement futur, on utilisera normalement une expression comme _be bound to_, et non _must_. (Ainsi, on dira _He's bound to be at home/He's bound to be working tomorrow_; _He must be at home/He must be working tomorrow_ exprimerait une obligation, et non une probabilité.


----------

