Modal Verbs

Modal Verbs:
Probability (co the xay ra) - Guess:
CAN, COULD, MAY, MIGHT (50%)
OUGHT TO, SHOULD (90%)
MUST (95%)
They might not beat the boy even though he doesn’t pay them
Permission: (cho phep): CAN, COULD, MAY, MIGHT
Can I go out?
May I go out?
Ability (kha nang): CAN, COULD, TO BE ABLE TO
Can you speak English?
_ Yes, I can speak English
Future (tuong lai): SHALL, WILL
She will finish high school
I will lock the door
Advice - Obligation (nen-bon phan): SHOULD
You should unlock the drawer
Strong Obligation (phai): MUST, TO HAVE TO, HAVE GOT TO
You must unlock the door
Moral  Obligation (phai-bon phan tinh than): OUGHT TO
You ought to obey your parents.
Politeness (chi lich su): WOULD
What would you like to drink?
Recommendation: HAD BETTER
Preference: WOULD RATHER
Habit: TO BE (GET) USED TO + Pre.P, TO BE (GET) ACCUSTOMED TO + Pre.P, USED TO + V (Past habit)

FROMs OF MODAL VERBS:
Modal Perfect  –  Modal + Have + Past Participle.
Modal Continuous -  Modal + Be + Present Participle
Modal Perfect Continuous -  Modal + Have Been + Present Participle

Ability (kha nang): CAN, COULD, TO BE ABLE TO
+ Modal Simple:
I could swim when I was young.
I was able to swim when I was young.
+ Modal Continuous:
I could be speaking French
+ Modal Perfect:
I could have told him to go/ toi co kha nang bao no di nhung toi da ko lam.
I could have spoken English when I saw him./Dung ra toi co the noi tieng anh luc gap anh ta.
Permission: (cho phep): CAN, COULD, MAY, MIGHT
+ Modal Simple:
She may have one day off now.
She was able to have one day off last week.
+ Modal Continuous:
She may be going tomorrow./ ngay mai co ta co le se di.
+ Modal Perfect:
She may have had one day off last week./ co ta co the da co 01 ngay nghi tuan truoc.
Strong Obligation (phai): MUST, TO HAVE TO, HAVE GOT TO
+ Modal Simple:
She must meet me today
She had to see me yesterday.
+ Modal Continuous:
She must be typing her report now.
+ Modal Perfect:
She should have been seen me yesterday./dang le co ta phai gap toi hom qua – ma co ta ko gap.
Preference: WOULD RATHER
We would rather have stayed home/dang le ta nen o nha.
Probability (co the xay ra) - Guess: MAY
She may have had one day off last week./ co ta co the da co 01 ngay nghi tuan truoc.
Advice - Obligation (nen-bon phan): SHOULD
I should have reviewed my lessons yesterday./Dang le hqua toi da on bai roi, ma toi lai ko.
Permission: (cho phep): CAN, COULD, MAY, MIGHT
May he have gone out last night?./Anh ay duoc phep co the da ra ngoai toi qua?