Take the 2-minute tour ×  We can use the following structure
with two different meanings. Does anyone know them?  Should +
have + p.p.  If you are familiar with these rules, then please
give me an answer. Since I am learning linguistics, I cannot
accept an irrelevant/informal answer.  Thanks in advance
share|improve this question If you don't know what the two
different meanings are, then how do you know there are two
different meanings? –  Jon Hanna Feb 13 at 17:50 Also, I don't
see how your learning linquistics applies, but it would seem
that you can never accept any answer at all. –  Jon Hanna Feb 13
at 17:53 I should have thought OP would have more sense than to
antagonise respondents by slagging off potentially irrelevant
answers before he's even seen them. He should have been more
deferential. –  FumbleFingers Feb 13 at 18:07 @FumbleFingers I
should have hoped it was a given that irrelevant answers
wouldn't be accepted, but if someone is to insist upon formal
answers then they should have written the q