While showing my work to my adviser, he uttered a sentence, "You could do it better!".
Is it analogous to:
You could have done better
OR
You can do it better (so improve it)?
It seems to me this sentence can mean both of these.
While showing my work to my adviser, he uttered a sentence, "You could do it better!".
Is it analogous to:
You could have done better
OR
You can do it better (so improve it)?
It seems to me this sentence can mean both of these.
The meaning of the comment depends on the context in which it is made. If the adviser is reviewing a draft of a paper or some other type of preliminary work, and says "You could do it better," the clear implication is that you could improve the work in one or more ways before turning it in for grading; presumably the adviser will then tell you generally or specifically what those ways are.
Alternatively, if the adviser is reviewing an exam or paper that you don't have the opportunity to retake or rewrite, "You could do it better" might just be a (not very helpful) remark to the effect that you didn't do as well on the assignment as you could have if you had studied harder, consulted the adviser in a timely fashion, or been perfect in every way. As an after-the-fact observation, the comment is pretty useless unless you want to use it as a reference quotation for self-recrimination.
I should note, too, that "You could have done better" (without the "it") is sometimes used idiomatically in English to mean simply "This isn't up to the standard that you're capable of [or that I expect of you]." For example:
Person 1: Have you met my new girlfriend?
Person 2: Yes. You could have done better.