TuongvanSituation1 :The window was broken yesterday .Now I ask Jim :
Who can / could have broken it ?
Who may have broken it ?
Who might have broken it ?
Your best choices here are:
Who [could / might] have broken it? Personally, I wouldn't use
may or
can.
TuongvanSituation 2 : I don't know whether Jack will come to Ann's birthday party or not.Now I ask my friend :
May Jack come to Ann's birthday party ?
Might Jack come to Ann's birthday party ?
Can Jack come to Ann's birthday party ?
Could Jack come to Ann's birthday party ?
You want to know "yes" or "no" about this, so your best choice is:
Is Jack coming to Ann's birthday party? A modal verb is not needed here.
can and
could focus on Jack's ability, and even if Jack is
able to come to the party, he might not come anyway, so that's not getting the answer you want.
may focuses on whether he has permission to come to the party, and you're not interested in that either.
might asks only if it's possible, and we can certainly assume that yes, he
might come to the party, and yes, he
might not come to the party, so that's not getting you anywhere either. (Every action in the universe either might happen or might not happen -- so to be told that something might happen is usually not to be told very much!)
TuongvanSituation 3: Jim said he would come here by 8 o'clock but now it is already 8.30 and we don't see him around here.Now I ask my friend:
Can /Could /might /may he have lost his way ?
In order, best first, I'd say
could, might, can. I wouldn't use
may here, though some speakers might. (I know you are interested in the usage of modal verbs, but again, a modal verb is not necessary:
Do you think he lost his way? The real meaning, I think, is not even a question, but more like:
I wonder if he (has) lost his way.)
______
In general, when speculating on the cause of something or on the identity of some unknown person or thing in the past, a question with could have is the best choice:
Who could have done it? What could have caused it? Could he have lost his way? Could anyone have predicted it? Where could they have put it? Where could I have seen it? How could you have forgotten it? Who could have taken it? Why couldn't they have brought it earlier? What could we have done differently?
CJ