Use of can, could, might, must, ought to for8 Standard
Can, Could : Asking for and Giving Permission
A) We normally use Modals such as could, can in sentences to ask and to give permission.
Ex.1) Preeti: Mama, I'm awfully hungry. can I eat these butter toasts ?
Mother : Why not? You can eat all of them if you like.
2) Vinay (to a neighbour) : Could I use your phone, please ?
Mr Bhushan : Yes, you're welcome.
- can ..... informal
- may..... formal
- could..... very polite
- But, the choise depends on the situation and the speaker's relation to the listener.
B) We also use can, could on Possibilities, Abilities
He can easily stand on his head. A computer can make lengthy calculations in ten seconds.
We could buy tickets in advance.
2. Can has only two forms- can(present) and can- (past)
She can do this exercise in five minutes.(present)
She could do this exercise in five minutes.(past)
- can/could- possibility; ability/capasity to do something in the present/past.
- could- general ability or permission to something.
Could is also used to make Suggestions: What shall we do this evening ? We could play carrom,we could even go to see a movie.
Could refers to the present; could have refers to some moment in the past;
I am so hungry, I could eat dozens of apples.(now)
I was so hungry, I could have eaten dozens of apples.(At some moment in the past)
We often use could have to talk about things which were possible but didb't happen: He slipped so badly on a banana skin, he could have hurt himself.(but he didn't)
- could do...... at the present moment
- could have done......... at some moment in the past (but didn't do)
Possibility : Might - He might be playing tennis.
- might is used to suggest possibility.But might suggests a lesser possibility than may.
- may.......a good possibility
- might........ a weak possibility
Necessity, Compulsion: Must
We use must to say that it is necesarry to do something.
You must put in real hard work if you want to do well.
Suggestion, Advice, Duty (obligation) :Should, Ought to
Ought to suggests that it is the right thing to do.
Ought to conveys the same sence as should . But it carries with it a sense of moral duty:
You ought to take care of your old parents.(It's your moral duty to................)
You ought to abide by the laws of the land .
- ought to......... moral obligation to do something.
I hope it helps!! Experts and friends thumbs up please!!!!!!