Student or Learner
I have some questions about grammar.
1) New students may not register for more than 3 classes.
Why can't we use (can) in this sentence? What does may mean in this sentence?
2) He casually asked‘Can I see that? ‘ , as if he was interested in my drawing.
Why can't we use may instead of can? What does can express?
3)I will be able to finish this assignment tonight.
I can finish this assignment tonight.
What is the difference between these sentences?
3) What is the difference between may and will when we express possibility? Are they the same?
4)It is necessary that we should leave
Can we omit should and that?<<It is necessary we leave.
5)You can't have finished already .What does this sentence mean? Is it in the present or in the past?
6) What is the difference between possibility and prediction?
It might be cold tomorrow.
It will be cold tomorrow.
7)They have had to wait for 2 hours.
They have to wait for 2 hours.
What is the difference between these 2 sentences?
8)I was glad that my computer could be repaired. Why can't we say could have been repaired ?