# Why isn't "to" needed here？（Infinitive）



## selfzhouxinrong

Hello，
Why isn't *"to"* needed here？（Infinitive）
Is there any deep reason? or historical reasons？

I don’t *let *my kids *to* *watch *violent movies. * ( make, have, let )*
I don’t *allow *my kids *to watch *violent movies
Thank you


----------



## berndf

The Proto-Germanic Infinitive was a declined neuter noun with nominative and accusative having the same form and genitive and dative having distinct forms. The bare infinitive is derived from the nominative/accusative infinitive. The _to_-infinitive is derived from an adverbial use of the noun linked to the preposition _to_ and in dative case. Modal verbs are the only cases left in modern English where the infinitive is formally a direct object, i.e. in accusative. In all other cases where a verb is used as an abstract noun, the gerund has replaced the infinitive, as in _I like swimming_ (not _I like *swim_), _Laughing is healthy_ (not _*Laugh is healthy_).

In sentences _I don't allow my kids to watch violent movies_, the infinitive phrase _to watch violent movies_ is syntactically an adverbial and is therefore derived from the historical dative infinitive.


----------



## gburtonio

But I guess the question is why _let_ uses this bare infinitive and _allow_ the _to_-infinitive. Ditto with _make_ _sb do_ vs. _force sb to do_. Something to do with the fact that _make_ and_ let _are from Old English and _allow_ and _force_ from French? (This obviously can't be a general rule though as there are of course plenty of verbs from Old English that aren't followed by the bare infinitive in Modern English.)


----------



## berndf

No, I don't think so. The same applies to inherited OE verbs as well, as in _I love to swim, I have to go_.

There is really only a limited number of verbs what can still take the infinitive as an object or as a predicative noun: _I will come, I can swim, I make him leave_.

In all other verbs you either use the gerund a_ to_-infinitive adverbial
_I love swimming
I love to swim_
whereas in OE one would have used the nominative/accusative infinitive:
_Ic lufige swimman _(=_I love swim_).


----------



## merquiades

But setting aside word order differences, the use of _zu_ + infinitive and infinitives alone seem similar in standard German.   Just that same small group of modals escape the _zu_.  So I deduce this must be something that occurred before old English, and before the language was gallicized.


----------



## gburtonio

berndf said:


> No, I don't think so. The same applies to inherited OE verbs as well, as in _I love to swim, I have to go_.
> 
> There is really only a limited number of verbs what can still take the infinitive as an object or as a predicative noun: _I will come, I can swim, I make him leave_.
> 
> In all other verbs you either use the gerund a_ to_-infinitive adverbial
> _I love swimming
> I love to swim_
> whereas in OE one would have used the nominative/accusative infinitive:
> _Ic lufige swimman _(=_I love swim_).



So just a weird historical quirk then?



merquiades said:


> But setting aside word order differences, the use of _zu_ + infinitive and infinitives alone seem similar in standard German.   Just that same small group of modals escape the _zu_.  So I deduce this must be something that occurred before old English, and before the language was gallicized.



The OED entry for 'let' notes that "A few examples of the use of to before the infinitive in this construction occur in all periods." The fact that modals and 'make' and 'let' are so frequent makes me suspect that the use of the bare infinitive was once the preferred structure and resisted a change to the _to_ infinitive that otherwise took place. Is that possible?


----------



## berndf

merquiades said:


> But setting aside word order differences, the use of _zu_ + infinitive and infinitives alone seem similar in standard German.   Just that same small group of modals escape the _zu_.  So I deduce this must be something that occurred before old English, and before the language was gallicized.


The main difference is that the German bare infinitive is still used as a verbal noun in the nominative and accusative cases.


berndf said:


> _I like swimming_ (not _I like *swim_), _Laughing is healthy_ (not _*Laugh is healthy_).


_Ich mag Schwimm*en*. Lach*en* ist gesund._

Of course, German also has the adverbial infinitive with _zu_.


----------



## berndf

gburtonio said:


> that the use of the bare infinitive was once the preferred structure and resisted a change *to the to infinitive that otherwise took place*. Is that possible?


Yes, either to the_ to_-infinitive or to the gerund. That's what I tried to explain. Sorry if it wasn't clear.


----------



## gburtonio

OK, so it's maybe somewhat analogous to the fact that the most frequent verb forms (e.g. _be_) tend to be the most irregular? Frequency of usage seems to provide resistance to language change and particularly to regularisation.



berndf said:


> Yes, either to the_ to_-infinitive or to the gerund.



Is it appropriate to hijack the thread here and ask if there is any historical pattern to the verbs that switched to taking the _to_-infinitive vs. those that switched to taking the gerund? Some have suggested there are underlying differences.


----------



## berndf

gburtonio said:


> Frequency of usage seems to provide resistance to language change and particularly to regularisation.


Yes, that seems to be the mechanism at work here.


gburtonio said:


> Is it appropriate to hijack the thread here and ask if there is any historical pattern to the verbs that switched to taking the _to_-infinitive vs. those that switched to taking the gerund? Some have suggested there are underlying differences.


The _-ing/-ung_ form is a common Germanic suffix that produces feminine, mostly abstract nouns from verbs. The precise meaning is not always predictable. E.g. the deverbal noun _surrounding_ does not the describe _the action of surrounding someone or something_ but it means _environment_. The grammaticalisation as a  verb form with the predictable meaning (the action of doing something) occurred in Middle English and is related to the merger in form with the present particle (OE _-nd-_ > ME _-ing_; e.g. OE _swimmende _> ME. _swimming_). There is an ongoing discussion whether the shift in meaning is due to the merger in form or whether the merger in form is due to the shift in meaning. But at any rate, the result was that the gerund replaced the bare infinitive as the standard way to express an abstract action.

The infinitive essentially only survived in its adverbial, the _to_-form; except for modal verbs.


----------



## Sobakus

berndf said:


> The infinitive essentially only survived in its adverbial, the _to_-form


What do you mean when you call _to_-infinitives 'adverbial'? Are you aware of some test where _to fly_ in "I like to fly" or "it's nice to fly" patterns with adverbs (adjuncts) instead of object/subject complements (arguments)? I can't fathom in what way "I like _to fly"_ patterns with "I like _at three o'clock_" as opposed to "I like _doughnuts"_.


----------



## berndf

Sobakus said:


> What do you mean when you call _to_-infinitives "adverbial"? Are you aware of some test where _to fly_ in 'i like to fly' or 'it's nice to fly' patterns with adverbs instead of object/subject complements?


Synchronically, this analysis is probably not terribly meaningful. But this a diachronical analysis and by "adverbial" I mean from a Proto Germanic or Old English grammar perspective. In OE, _to swimmanne_ was clearly an adverbial (preposition+dative noun).


----------



## selfzhouxinrong

Thank you all  

So...Why isn't *"to"* needed here？

I don’t *let *my kids *to* *watch *violent movies.         *( make, have, let ) also（see, hear, help, etc.）*
But in the passive voice, we still need "to" ?

and what the different between "help sb do" and "help sb to do"?

Thank you！


----------



## gburtonio

selfzhouxinrong said:


> Thank you all
> 
> So...Why isn't *"to"* needed here？
> 
> I don’t *let *my kids *to* *watch *violent movies.         *( make, have, let ) also（see, hear, help, etc.）*
> But in the passive voice, we still need "to" ?
> 
> and what the different between "help sb do" and "help sb to do"?
> 
> Thank you！



Well, the short story seems to be that the form without 'to' reflects an older syntactic construction, one that has generally disappeared except with modals, _make_ and _let_ (because these are all particularly frequent and therefore perhaps resisted the change).

'Help' and 'have' are interesting in that both forms coexist: in the case of 'have' with different sense meanings (i.e. have + *to* + *infinitive* and have +* infinitive* are both possible, along with have +* past participle*, have + *gerund*, but with differences in use/meaning); in the case of 'help' with no difference in meaning (to answer your final question).


----------



## Sobakus

berndf said:


> Synchronically, this analysis is probably not terribly meaningful. But this a diachronical analysis and by "adverbial" I mean from a Proto Germanic or Old English grammar perspective. In OE, _to swimmanne_ was clearly an adverbial (preposition+dative noun).


I don't think answering the OP's question in this way is much more desirable than telling someone asking about the difference between two words by saying that one of the words means a totally different thing, only to omit that this was true a millennium ago, while today the difference is in register instead. I believe this is called the etymological fallacy.

By some coincidence I came across a term/descriptive framework that aims to answer this exact question the day before it was posted - Catenative verbs. These verbs are on a continuum between pure auxiliaries like _to have/be_ and fully lexical verbs like _to leave_. Not taking _to-_infinitives as objects is just one of their possible restrictions - in fact they might be underlyingly inheriting grammatical structure from the full verb to which they're joined (incorporation). The lexical verb they're joined to cannot be negated separetly, and they can't be passivised:

_I don't allow my kids to watch TV  I allow my kids to not watch TV _​_I don't let my kids watch TV  I let my kids not watch TV  I let my kids to not watch TV _​_I wanted him to not sleep _​_My kids were allowed to watch TV  My kids were let to watch TV _​_He was wanted to sleep _​​Also observe the shift: _I can [not sleep]_  >> _[I cannot] sleep_  = underlyingly _[I not-can] sleep_​
There's definitely some grammatical incorporation going on with these, and as such they might feel quite familiar to Mandarin speakers. There's various tests to detect them and not all verbs that pass one test will pass all the others - so there's no clear-cut division between catenatives on the one hand and auxiliaries or "normal" verbs on the other. The fact that catentaive verbs like _let_ are sometimes found with _to-_infinitives is a reflection of this - cf. that _I let my kids to not watch TV_ is a (borderline) grammatical sentence.

As you can see, attempting a synchronically valid explanation reveals much deeper grammatical difference than simply skipping the particle _to_ (apparently some analyse it as a full verb!).

Here's a useful downloadable list of these verbs.
Here's a readable linguist-friendly 16-page discussion demonstrating their various properties.

Disclaimer: since most of my understanding is derived from reading part of that article and a bit elsewhere, some of what I write above is arguable or even false. I wanted to read on this more before replying, but whatever - this still works as a general summary.


----------



## berndf

Sobakus said:


> I don't think answering the OP's question in this way is much more desirable than telling someone asking about the difference between two words by saying that one of the words means a totally different thing, only to omit that this was true a millennium ago, while today the difference is in register instead. I believe this is called the etymological fallacy.


You realize that we are in the etymology forum here and that the question was how the situation originated? I am convinced there is no logical explanation for it it is just the way it is and it is indeed just a historical quirk.


----------



## Sobakus

berndf said:


> You realize that we are in the etymology forum here and that the question was how the situation originated? I am convinced there is no logical explanation for it it is just the way it is and it is indeed just a historical quirk.


Yes I am, and I'm all for etymology. "A millenium ago they were adverbials of purpose" is indeed a valid explanation; "to-infinitives are adverbials" is not,* and that wasn't just a single slip of the tongue, hence my remark.
* modern English still has to-adverbials of purpose, which can be substituted with "in order to": _He thinks (in order) to exist._

In principle, one can't be convinced that there is no logical explanation before one has explored all the logical explanations. The real problem is that it would be naive to believe that one has explored all the possible logical explanations in the first place - in science, a new logical explanation is always around the corner.


----------



## berndf

Let's put it this way: I am convinced there is no logical explanation and therefore I only answered the portion of the question that is concerned with how it evolved and I wouldn't even try to construct a synchronic explanation. If you think there is a logical reason by all means give it a try.


----------

