# How could you ... / How could you have ...



## VicNicSor

Joanna learns that her husband deliberately left her in the hospital with amnesia. She:
-- How could you do that? How could you be such a slime?
Overboard, movie

I guess that_ How* could you have done* that? How *could you have been* such a slime? _would be incorrect here,  am I right?
Thanks.


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## tomtombp

I agree that they are incorrect.

"You could have done something" means you could have done it but you didn't.


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## VicNicSor

No, _How* could you have done* that? _doesn't mean _you didn't do that_. I think it has more to do with the speaker's great surprise at what they have learnt.


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## Myridon

They are correct as-is.  The question is not so much "how were you able to do that then?" but "how are you able to do that ever?"


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## VicNicSor

Myridon said:


> They are correct as-is.


Do I correctly understand both How could you ... ? and How could you have ... ? would work in the OP with the same meaning?



Myridon said:


> The question is not so much "how were you able to do that then?" but "how are you able to do that ever?"


But this question is about something that *has happened*. Otherwise, she would say "can", am I wrong?


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## tomtombp

VicNicSor said:


> No, _How* could you have done* that? _doesn't mean _you didn't do that_."



All grammar sites I've checked say this:
"We can use 'could have'  to talk about something somebody was capable of doing but didn't do."

Am I missing something?


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## VicNicSor

tomtombp said:


> Am I missing something?


Yes, e.g., look at this one from Collins Cobuild:
15) (emphasis) In speech, you use _how could_ in questions to emphasize that you feel strongly about something bad that has happened. _How could you allow him to do something like that?... *How could I have been* so stupid?... How could she do this to me?...* How could you have lied *to us all these years?_


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## tomtombp

VicNicSor said:


> Yes, e.g., look at this one from Collins Cobuild:
> 15) (emphasis) In speech, you use _how could_ in questions to emphasize that you feel strongly about something bad that has happened. _How could you allow him to do something like that?... *How could I have been* so stupid?... How could she do this to me?...* How could you have lied *to us all these years?_



Thanks, good to know. Doesn't this also answer your OP question? Why did you suppose "_How* could you have done* that"_ was incorrect knowing about this usage?


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## VicNicSor

tomtombp said:


> Thanks, good to know. Doesn't this also answer your OP question? Why did you suppose "_How* could you have done* that"_ was incorrect knowing about this usage?


Because I thought the difference was:

*Could have*: How was it possible that you did that?
*Could*: How were you able to do that?

So I thought the former didn't work.


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## Glasguensis

How could you have done that and how could you have been such a slime are entirely possible and could have been used instead of the actual dialogue with no real impact on the meaning.


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## VicNicSor

Glasguensis said:


> with no real impact on the meaning


But if there is even a very slight one, was I right in #9 as to the difference between them?


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## Glasguensis

No. Here, the meaning is determined by the context and tone, not by the verb form.


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## VicNicSor

Glasguensis said:


> No. Here, the meaning is determined by the context and tone, not by the verb form.


Look please at this definition I quoted in #7:
In speech, you use *how could* in questions to emphasize that you feel strongly about something bad that has happened.
_*How could *you allow him to do something like that?... _
_*How could *I *have *been so stupid?... _
_*How could* she do this to me?... _
_*How could *you *have *lied to us all these years?_

Do you mean that generally, in the context of "emphasizing that you feel strongly about something bad that has happened", I can use 'how could' and 'how could have' absolutelly interchangeably (for example, in the Collins's examples above)?


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## srk

Glasguensis said:


> No. Here, the meaning is determined by the context and tone, not by the verb form.





VicNicSor said:


> *Could have*: How was it possible that you did that?
> *Could*: How were you able to do that?


In a different context, both "could" and "could have" might be about ways and means.  "How could you have opened a drawer like that one -- one that was stuck tight."  "How could you open a drawer like that one -- one that is stuck tight?"


VicNicSor said:


> Do you mean that generally, in the context of "emphasizing that you feel strongly about something bad that has happened", I can use 'how could' and 'how could have' absolutelly interchangeably


Yes, for either ways and means or as in your Collin's examples.

Edit: I made a change (in blue).


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## VicNicSor

Thank you everyone!


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## Phoebe1200

srk said:


> "How could you have opened a drawer like that one -- one that was stuck tight."


Hi, srk. In this sentence, aren't we talking about the ability, that he was able to open it?


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## Glasguensis

Yes, which is what srk was saying.


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## Phoebe1200

Glasguensis said:


> Yes, which is what srk was saying.


Then why use the perfect form could+have?


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## Englishmypassion

Myridon said:


> They are correct as-is.  The question is not so much "how were you able to do that then?" but "how are you able to do that *ever*?"



So you mean the "could" in "How could you do that?" doesn't express the past tense but the universality of time. Right?

Thanks.


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## Glasguensis

Phoebe1200 said:


> Then why use the perfect form could+have?


Because it refers to an action in the past. 



Englishmypassion said:


> So you mean the "could" in "How could you do that?" doesn't express the past tense but the universality of time. Right?
> 
> Thanks.


It can mean both, depending on the context.


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## Englishmypassion

Glasguensis said:


> It can mean both, depending on the context.



Thanks a ton. I mean in the OP's context.


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## Phoebe1200

Glasguensis said:


> B beecause it refers to an action in the past.


I'm lost here. Shouldn't it be *How could you open a drawer like that one?* as in a past ability similar to _I could speak Spanish when I was a kid._


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## Glasguensis

Englishmypassion said:


> Thanks a ton. I mean in the OP's context.


Yes, that's how it's being used in the OP.

@Phoebe1200 
It's just not what we say.


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## Englishmypassion

Glasguensis said:


> Yes, *that's how* it's being used in the OP.



Sorry to give you trouble again but the "that's how" is a little murky there, in continuation of the above posts. You mean in the OP's context, (_How could you do that?_)"could" has been used to show the universality of time, not the past tense. Right?


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## Glasguensis

Yes.


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## Englishmypassion

Thanks a ton, Glasguensis. You have been very kind and helpful and I'm much obliged to you.


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## VicNicSor

Sorry, but to me, it seems like making things more complicated than they are. The act of leaving her happened in the past, the speaker and listener both are aware of that. And we know that "How could you (do something?)" is pretty well used talking about actions in the past in such contexts. If she'd meant "ever", she would've said something like that.


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## Glasguensis

She did say something like that. That's what "how could you do that" means here.


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## VicNicSor

(1) "Could" is the past tense of "can", (2) they're talking about the past, otherwise, wouldn't it have been like:
How can you do things that? How can you be such a slime?

I'd expect "How *could *you do that?" meaning "ever" in a different context: You are going to do something which I believe is a difficult thing to do, and I doubt you will able to do that and so I ask...


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## Glasguensis

There is no central authority in English which defines correct usage. Any guidance or definition you find here or in a dictionary reflects how native speakers actually use the language. We are telling you that this is one of the ways we actually use the language. You are free to not use it, but if you do not recognise that this is a legitimate usage you risk misunderstanding native speakers.


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## VicNicSor

Sorry, I just don't understand one thing. You said "It can mean both, depending on the context.", and said that in this context it means, as EMP said, "the universality of time". But why, in this context, doesn't it refer to specific events in the past? Wouldn't that be logical?...


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## Englishmypassion

VicNic, I took Glasguensis's explanation to mean that the speaker is focusing and commenting on the listener's innate nature in general rather than an incident (in the past). Don't you take that?

Edited: To change "Do" into "Don't" to express the intended meaning better/correctly.


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## VicNicSor

Yes, that's why I asked


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## VicNicSor

Hello GS, it's an old thread, so I am not able to


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## Glasguensis

VicNicSor said:


> Sorry, I just don't understand one thing. You said "It can mean both, depending on the context.", and said that in this context it means, as EMP said, "the universality of time". But why, in this context, doesn't it refer to specific events in the past? Wouldn't that be logical?...


No. She is not questioning his physical capacity but his emotional capacity. If she were asking about this one instance only, that would imply that she is able to imagine other circumstance where abandoning her at the hospital would be perfectly acceptable. Given the context, it seems unlikely that this is what she means - she is questioning how he is capable of ever behaving in this way. But in a different context it could well refer to a specific instance. This isn't really a question of grammar or definition - it is how we understand the phrase given the context.


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## VicNicSor

Glasguensis said:


> No. She is not questioning his physical capacity but his emotional capacity. If she were asking about this one instance only, that would imply that she is able to imagine other circumstance where abandoning her at the hospital would be perfectly acceptable. Given the context, it seems unlikely that this is what she means - she is questioning how he is capable of ever behaving in this way. But in a different context it could well refer to a specific instance. This isn't really a question of grammar or definition - it is how we understand the phrase given the context.



Sorry but why must we take the meaning of "could" here so literally? I thought it's just an expression, "How *could *you (do something?)", said when you are angry at someone for what they've done. And in dictionaries, under "could", this meaning usually comes as a separate meaning...


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## Glasguensis

I don't understand your point.


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## Phoebe1200

srk said:


> "How could you have opened a drawer like that one -- one that was stuck tight." "How could you open a drawer like that one -- one that is stuck tight?"


Hi. Could you please tell me the meaning behind _could_ in each of the above sentences? Is it 
a past ability, possibility, the universality of time?
I'm super confused here.


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## srk

Phoebe1200 said:


> Hi, srk. In this sentence, aren't we talking about the ability, that he was able to open it? (post # 16)


You made the right assumption in post #16.  "Could" is about possibility or ability in both sentences.  To make sure the sentences would be interpreted that way, I appended the part about the drawer being stuck tight.  I could have written "How could you have been able to open a drawer like that one" or "How could you be able to open a drawer like that one" with the same meaning.

"How could you possibly have opened that drawer" or "How could you possibly open that drawer" depend on intonation and context for meaning.  They might be about possibility or ability, but they might also be about shock and distaste at the drawer opener's lack of respect for the owner's privacy, for example.  The word "possibly" here can be about feasibility, or it can just emphasize the speaker's displeasure.


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## Phoebe1200

srk said:


> You made the right assumption in post #16.  "Could" is about possibility or ability in both sentences.  To make sure the sentences would be interpreted that way, I appended the part about the drawer being stuck tight.  I could have written "How could you have been able to open a drawer like that one" or "How could you be able to open a drawer like that one" with the same meaning.
> 
> "How could you possibly have opened that drawer" or "How could you possibly open that drawer" depend on intonation and context for meaning.  They might be about possibility or ability, but they might also be about shock and distaste at the drawer opener's lack of respect for the owner's privacy, for example.  The word "possibly" here can be about feasibility, or it can just emphasize the speaker's displeasure.


Hi, srk. You know I read over your post a few times but it's still unclear to me. It'd be really great if you could just tell me exactly what meaning of *could* you have in mind for each of these sentences:
       "How could you have opened a drawer like that one -- one that was stuck tight." 
       "How could you open a drawer like that one -- one that is stuck tight?"


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## Phoebe1200

I'm sorry, but since when *could+have* is used to express a past ability?


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## srk

Phoebe, I deleted my post, because there were things I didn't like about my answer.  "Could + have" expressing past ability was not one of them:  I could have run faster yesterday than I ran today.

Let me think and post a better answer.


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## srk

Phoebe1200 said:


> It'd be really great if you could just tell me exactly what meaning of *could* you have in mind for each of these sentences:
> "How could you have opened a drawer like that one -- one that was stuck tight."
> "How could you open a drawer like that one -- one that is stuck tight?"


"Could you have opened that drawer?" can mean "Were you capable of opening that drawer?"  (This is "could + have" expressing past ability.)  It follows that "How could you have opened that drawer?" can mean "How were you capable of opening that drawer?"

"Could you open that drawer?"  can mean "Are you capable of opening that drawer?"  It follows that "How could you open that drawer?" can mean "How are you capable of opening that drawer"

These are the meanings of "could" that I had in mind for the sentences you asked about. ("Could you have opened that drawer?" can also mean "Is it possible that you were the person that actually opened the drawer?  It doesn't particularly fit with with the idea of a drawer that is stuck.)

Understand that I am not recommending these sentences as best examples.  I'm only trying to show that questions like "How could you have opened that drawer?" are not necessarily full of accusation like the ones in the OP.  They can be very straightforward questions about capability or possibility.



Phoebe1200 said:


> I'm sorry, but since when *could+have* is used to express a past ability?



I don't have that answer.  It has been a while.


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## Phoebe1200

Hi. I'd like to clarify some things again.
*I could have opened that drawer. *(Is this a past ability for you?)
*How could you open that drawer?* (Are you referring this to a present/future tense or past?)
And is ability and capability the same thing in regard to the use of modal verb _can/could _when for instance we say *I could speak Spanish when I was a child* (Does this mean that-I was able to speak Spanish=I was capable of speaking Spanish)?
Thanks.


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## srk

Phoebe1200 said:


> *I could have opened that drawer. *(Is this a past ability for you?)


It can be understood in a few ways:  "I was capable of opening that drawer."  "I don't remember whether or not I opened that drawer.  Maybe I did."  "You didn't have to open that drawer.  I could have done it for you."  "I would have been able to open that drawer if someone had asked me to."  There may be others, but all of them are about a past ability.


Phoebe1200 said:


> *How could you open that drawer?* (Are you referring this to a present/future tense or past?)


It is either about the present, the future, or without reference to time.  I don't think there's a way to understand it as clearly referring to the past.  (If the drawer is open, there's an implication in the question that the person addressed had opened it in the past.)  That accounts for "How could you have opened that drawer?" as one way to use "could" to _clearly_ refer to the past.


Phoebe1200 said:


> And is ability and capability the same thing in regard to the use of modal verb _can/could _when for instance we say *I could speak Spanish when I was a child* (Does this mean that-I was able to speak Spanish=I was capable of speaking Spanish)?


Yes.  I don't know how else to understand it.


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## Phoebe1200

Are you saying that I can't use *I could open that drawer *as a past ability?


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## srk

Phoebe1200 said:


> Are you saying that I can't use *I could open that drawer *as a past ability?


You can if you add something like you did for speaking Spanish:  "I could open that drawer when I was a child."  Without something like that, it is hard to read the sentence and understand it as referring to the past.


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## Phoebe1200

srk said:


> You can if you add something like you did for speaking Spanish:  "I could open that drawer when I was a child."  Without something like that, it is hard to read the sentence and understand it as referring to the past.


How about?
_I could open that drawer yesterday._


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## srk

That's fine.


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## Phoebe1200

srk said:


> That's fine.


You know, the reason I asked is because there is this rule on some websites that says: _*"Could" cannot be used in positive sentences in which you describe a momentary or one-time ability*, *unless it's used with verbs of the senses.*_

         e.g _When the computer crashed yesterday, I was able to fix it.(not 'I could fix it')_

What do you think?


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## Glasguensis

Indeed it would not be idiomatic in that sentence, because although  "yesterday" is not a momentary period, "when the computer crashed" is. Teaching websites often give rules of thumb which prevent you making mistakes, but that doesn't mean that you can never do what they tell you to avoid, merely that it's too hard to explain the exceptions.


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## JulianStuart

Phoebe1200 said:


> How about?
> _I could open that drawer yesterday._


Yes.  Today it's stuck and I can no longer get it open, but yesterday I could get it open.
All fine


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## Phoebe1200

Glasguensis said:


> Indeed it would not be idiomatic in that sentence, because although "yesterday" is not a momentary period, "when the computer crashed" is. Teaching websites often give rules of thumb which prevent you making mistakes, but that doesn't mean that you can never do what they tell you to avoid, merely that it's too hard to explain the exceptions.





JulianStuart said:


> Yes. Today it's stuck and I can no longer get it open, but yesterday I could get it open.
> All fine


Hi. 
And what about this example provided by www.englishpage.com that says I can't use "could" here:
*Yesterday, I could lift the couch by myself.*


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## JulianStuart

Phoebe1200 said:


> Hi.
> And what about this example provided by www.englishpage.com that says I can't use "could" here:
> *Yesterday, I could lift the couch by myself.*


Your link does not take me to that example.
Yesterday I could lift the couch by myself, but today I need help because I sprained my wrist.

The WRF dictionary has, as its first entry under could - past tense of "can".



> WordReference Random House Learner's Dictionary of American English © 2016
> can1 _/kæn; unstressed kən/_ _auxiliary (modal) verb. All present tense forms_: *can,* past: *could.*
> auxiliary verb [~ + root form of a verb]
> 
> to be able to;
> have the ability to: * She can solve the problem easily.*





> WordReference Random House Learner's Dictionary of American English © 2016
> could _/kʊd; unstressed kəd/_  auxiliary (modal) verb. [~ + root form of a verb]
> 
> the past tense of can1:*Once I could run five miles a day*.


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## Phoebe1200

JulianStuart said:


> Your link does not take me to that example.
> Yesterday I could lift the couch by myself, but today I need help because I sprained my wrist.


Sorry about that. ENGLISH PAGE - Could


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## JulianStuart

They use it as an example of _"Could" cannot be used in positive sentences in which you describe a *momentary or one-time ability*._"
It is a poor example: Yesterday, as I was trying out furniture arrangements in my new apartment, I moved the couch many times - I had the ability to move the couch, and it was not momentary or "one-time".

A better example of the point they are making might be

Yesterday I could stop the freak accident at work.
Yesterday I couldn't stop the freak accident at work.

The freak accident is the onetime "thing" I was not able to stop.


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## Phoebe1200

JulianStuart said:


> They use it as an example of _"Could" cannot be used in positive sentences in which you describe a *momentary or one-time ability*._"
> It is a poor example: Yesterday, as I was trying out furniture arrangements in my new apartment, I moved the couch many times - I had the ability to move the couch, and it was not momentary or "one-time".
> 
> A better example of the point they are making might be
> 
> Yesterday I could stop the freak accident at work.
> Yesterday I couldn't stop the freak accident at work.
> 
> The freak accident is the onetime "thing" I was not able to stop.


Hello Julian Stuart.
First of all, thank you for your explanation. You made a good point about the couch example because if I was able to lift it once then that means that I have the ability to do it any time. And if that's the case it makes it a general ability. So my question is if I have that in mind, can I use it like this: 
*Yesterday, I could lift the couch by myself.*


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## Glasguensis

Yes.


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