can,could,might同may既分別

can,could的分別當然是present tense(can) 和 past tense(could).而他們的意思係！可以！
might,may的分別當然是present tense(may) 和 past tense(might).而他們的意思係！可能！

例句：The classroom can seat thirty students.
這教室可以坐三十位學生。
這句係很定的，即係一定能夠坐三十位學生
而
The classroom may seat thirty students.
這教室可能坐三十位學生。
這句係唔很定的.

分別就係呢到！！！！！

Can
1.Ability
She can make her own dress
2.Permission and refusal
You can go when you have finished the exercise.
You cannot leave the classroom until the bell rings.
3.Impossibility
It cannot be true.
4.Possibility colored by incredulity
Can this be true?
5.Impatience and puzzlement (emphatic can)
Where can he have got to?
Where can he be?

Could

1.Ability
I could speak English when I was five years old.
2.Polite request
Could you tell me the time?
3.Reported speech
He said he could sing.
4.Possibility and impossibility
I know what he said could not be true.
5.Impatience (stressed)
Where could it be? I saw it only this morning.
6.Exaggerate in order to stress feelings
I could eat a horse!

May

1.Permission
You may go.
2.Possibility (with stress)
It may be true.
3.Uncertainty or conjecture
It may have been raining in the north this morning.
4.Reasonableness
We may expect a good harvest.
5.Light prohibition
You may not go out tonight.
6.Condescension or superiority
And who may you be?
7.Exclamatory wish
May you live to repent it!
May god bless you all!

Might

1.Possibility
I might visit him if I feel like it.
He might come tomorrow.
2.Reported speech
He said I might borrow this book.
3.Permission
I came to ask if John might borrow your bicycle tomorrow.
4.Polite request
Might I use your phone?
You might post this letter for me
5.Hesitant suggestion
It might be better for you to retire at sixty.