Question

みたらし

以下の問題の意味のどこが違うのかわかりません！教えて下さい

ii A1 Discuss the difference in meaning between these sentences:
1 They might tell me but ...
They might have told me but ...
We could have tea early because
You mustn't tell her that ...
You needn't tell her that ...
2
3
...
4 I should have trusted him but
I shouldn't have trusted him but
I needn't have trusted him but
5 She can't have lunch because ...
She couldn't have lunch because
6 He may not have seen her, so
He may not be seeing her, so...
He may not see her, so
...
They may have told me but ...
They may tell me but
We were able to have tea early because ...
You don't have to tell her that
You oughtn't to tell her that
I had to trust him but ...
I didn't have to trust him but ...
...
She can't be having lunch because
She can't have had lunch because
He can't have seen her, so ...
He can't be seeing her, so...
He can't see her, so ...