grammar

[jiang]

Is the sentence 'You can't have seen him last week. He was in New York' correct? Shouldn't it be 'couldn't' instead of 'can't' since it is 'last month'?

[Casiopea]

Originally Posted by jiang

Is the sentence 'You can't have seen him last week. He was in New York' correct? Shouldn't it be 'couldn't' instead of 'can't' since it is 'last month'?

You couldn't have seen him. (could, past; seen, past)

You can't've.... (non-standard, moving towards slang)

:D

Originally Posted by jiang

Is the sentence 'You can't have seen him last week. He was in New York' correct? Shouldn't it be 'couldn't' instead of 'can't' since it is 'last month'?

I think the "can't have + past participle" form is used mostly in British English. I would wait for a BE speaker to comment on that.

It exists in American English, but as I can recall, it's not something I've heard or read often at all.

Here is a link to that form on a grammar site.

It also has a relatively small amount of hits on Google. The form exists, but it's simply not something one often encounters in Amercan English. I think your best bet is to stick with "couldn't have + past participle". This is the form that you will mostly come across in reading and conversation, I would say. Actually, that is what I say.

If you've been told before that this form is wrong, it is probably because most people are not accustomed to it. I can tell you it's not something I would be likely to say or write at all. I have to say "couldn't have + past participle" is the form that is used most often between the two. I would also say they mean the same thing.

I'd wait for a BE speaker to comment on "can't have + past participle" as well.


http://www.geocities.com/suzkeadie/m...eednthave.html

"can't have seen"

http://www.google.com/search?hl=en&i...=Google+Search


"couldn't have seen"

http://www.google.com/search?hl=en&l...t+have+seen%22

[Tdol]

You can't have is perfectly normal BE. The positive is not used, we would use must have instead.

Originally Posted by tdol

You can't have is perfectly normal BE. The positive is not used, we would use must have instead.

You can't have seen him - It was not possible that you saw him. - I don't think/believe it was possible.

You couldn't have seen him - It was not possible that you saw him. - I don't think/believe it was possible.

You could have seen him. - It was possible that you saw him. - I think it was possible that you saw him.


I don't understand how "You must have seen him." is used as the opposite of "You can't have seen him."

Does the "can't have+past participle" form carry the same meaning as the "couldn't have+past participle" form to you?

I will say that "can't have+past participle" is not very common at all in American English. I can't really recall ever hearing it. I might have read it, but that would be it.

[Tdol]

I'd say it is equal to 'You couldn't possibly have seen him'. The present offers more certainty.

Originally Posted by tdol

I'd say it is equal to 'You couldn't possibly have seen him'. The present offers more certainty.

Okay, but I still don't quite get how in BE "must have+past participle" would be taken to mean the opposite of "can't have+past participle".

couldn't have seen him - opposite = could have seen him

can't have seen him - opposite = could have seen him

can't have seen him - How would we know that "You must have seen him." is true or likely simply because "You can't have seen him." is not true or doesn't apply?

[Tdol]

can't have = impossible
must have = certain

Originally Posted by tdol

can't have = impossible
must have = certain

Then where would you go to simply say "possible" in opposition to "can't have", which means impossible?

[Tdol]

can't have
may have
must have

?