Wow! Bokeh, thanks for the contribution, I didn't know that

I got very confused because I have never looked "shouldn't have done" as a present perfect form, so now I understand what you mean because it actually is present perfect tense, but I always see it as "being regretful".. So, just ignore my previous

Yes, that "Hasn't John had to do that?" question is absolutely more understandable! But... oh Marius you were faster than me! I was gonna say that I didn't know such usage actually, we always use "don't have to", "didn't have to".. But, it is a

Yankee, if you hadn't written the explanation of that "must John not have done that?", I wouldn't have understood what it means. It really is complicated. I guess I'll go on with "John must not have done that???"

Thank you Yankee! And thanks GG for clarification! I understand now. Phew.. this question was on my mind for -maybe- months, I am happy that it is resolved

I want to know how to form negative questions with shouldn't and mustn't.

Thanks for the quick answer Okay, so the negative question would be "Shouldn't I have done that?"

Hello , My sentence is: I shouldn't have done that . I want to make it a question, but I cannot. I searched google to find a question sentence includes that (I tried many alternatives ), but couldn't find anything. I started to think that maybe

<<More questions: Who are we? I can say that "we" is the all living creatures in the universe. Where do we come from? nothing.. hmm. there are other theories too, no one knows the answer exactly. Where we are going to? no one knows,

Avril Lavigne's "girlfriend" : stupid, childish and meaningless.