Our dog escaped! You can't have shut the door properly!

Does the phrase 'You can't have shut the door properly!' mean 'You must have shut the door in a wrong way', or 'you haven't been able to shut the door properly'?

  • The former. It simply means you haven't shut the door. It says nothing about your general ability or chances. – RegDwigнt May 18 '15 at 10:12
  • Is it correct to simply say 'You haven't shut the door properly!' in this case without loss of meaning? And if I want to say about my general ability in past, how can I use can't\couldn't + perfect form? – kacherese May 18 '15 at 10:22
  • "You can't have shut the door properly" is a perfectly acceptable (probably preferable, as it is a shade more polite) way to say "I don't think you shut the door properly." It is more likely to be heard in British English. – Robusto May 18 '15 at 11:08
  • The phrasing is atypical for modern American English, though it was seen in old Bobbsey Twins books (ca 1920) and the like. (More modern would be "You must not have shut the door properly.") It implies that (some time in the past, not at the present moment) the door was not shut properly for some reason. – Hot Licks May 18 '15 at 12:24
  • This is the Epistemic sense of can, which is a negative polarity item (and therefore can occur grammatically only in the negative -- whence can't). Note that trying to use can instead of can't produces an anomaly; may is the epistemic possibility modal that's used in the affirmative, not can. Note that can't means 'not possible', while may not means 'possible not'; this is one reason why we have a lot of modal auxiliaries. – John Lawler May 18 '15 at 18:19

You can write it differently, while keeping the "can't":

It can't be that you shut the door.


It's impossible that you shut the door.

So, s/he wasn't unable to shut the door, just didn't do it.
If you want to express the inability to shut it:

You can't shut the door, or
You couldn't shut the door.


Since the sentence appears to refer to a single escape incident, "You can't have shut the door properly!" is more properly described by: "You must have shut the door in a wrong way" - which refers to a single incident- than by: "you haven't been able to shut the door properly", which implies more than one instance of gate-shutting incompetence.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.