I read the first sentence on FB (I know, this is not the right place to look for perfect grammar) and would like to know if this is right:

I can't sleep well since last week

I thought a construction like this needs the present perfect 'have been':

I haven't been able to sleep well since last week

The person who wrote the first construction is a native speaker of English which is why I'm so confused. Is it slang or just another way of saying it?

3 Answers 3


This is a good lesson that you can't always trust what native speakers write. Of course, sometimes it's impossible to know if the odd grammar is just slang or laziness.

You are correct, and the sentence should be:

I haven't been able to sleep well since last week.

to indicate an ongoing condition, or simply

I can't sleep well.

to indicate a present condition.

  • 4
    Side note: This is the sort of thing people say when they change their minds halfway through a sentence. I can imagine saying "I can't sleep well", and then deciding that I need to make clear the time frame, and so adding "since last week". In speech, it's too late to go back and unsay the beginning of the sentence. In writing, sometimes we're too lazy to bother, or we just don't think about it.
    – Jay
    Jan 3, 2017 at 20:24
  • @Jay Agreed, I also thought the same thing. OP said this was posted to Facebook so the writer could have edited, but laziness won out :)
    – Andrew
    Jan 3, 2017 at 20:29
  • 2
    can't ... since is also used colloquially where since means because. Example: I can't sleep well since i saw the horror movie.
    – erikdstock
    Jan 3, 2017 at 20:44
  • 1
    You also might hear: "I haven't been sleeping well since last week" or "I haven't slept well in the last week".
    – BradC
    Jan 3, 2017 at 21:37
  • @erikdstock: IMO that is not an example of "since" being used in place of "because". Jan 4, 2017 at 1:32

Well, it depends on who you ask. In general, there are two schools of thought when it comes to linguistics: prescriptivism and descriptivism.

Prescriptivists would say…

  • language rules exist in an explicit form in a codified standard (“the norm”);
  • people say utterances based on these codified rules;
  • the correct form is determined by what the standard is;
  • ergo, if a form is correct, native speakers should use it.

Descriptivists would say…

  • language rules exist in an implicit form in subconsciousness of its users (“the usus”);
  • people say utterances based on these subconscious rules;
  • the correct form is determined by how people speak;
  • ergo, if native speakers use a form, this form is correct.

So, in short, a prescriptivist would say that the first form doesn't follow the codified rules, thus, it is incorrect. On the other hand, a descriptivist would say that since the first one is used more often than the other one, it is a better description of the usus.

While the first line of thought (prescriptivism) might seem to you more down-to-earth and that's probably what you have been taught at school, the second one (descriptivism) is the one regarded more scientific in academic circles (and probably subscribed to by more professional linguists).

TLDR: a linguist will likely say it is correct (because a native said so), while a pedagogue will likely say it isn't. There is no common approach.



I can't been able to sleep well since last week

because you don't have it, you can or can't do it.


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