Can, Could and (be) able to CanBe able toAbility possible allowed E.g. I can swim. E.g. I am able to swim. “can” is more usualE.g. You can see a beautiful if you open the window. (possible) E.g. She can take me to her heart. (allowed) E.g. I can cookvery well. (ability)If you want to make negative, you can write “can’t or cannot”. E.g. I am very sad that you can’t come to my birthday. When we cannot use “CAN”, we have to use “BE ABLE TO”. Present Perfect [can (present) and could (past), no present perfect form for “can”] E.g. I haven’t been able to sleep recently. If there is a Helping Verb (or) Auxiliary Verb in a sentence, we cannot use “can”. E.g. Tom might be able to come tomorrow. Can (present) = Could (past) using with see hear smell taste feel remember understand Could general ability E.g. My grandfather could speak five languages. Was/were able to (or) managed to specific situation (when we get ‘permission’) E.g. We didn’t know where David was, but we managed to find/were able to find him in the end. Negative for “could”: couldn’t (for all situations) E.g. My grandfather couldn’t swim. Could (do) and could have (done) Can(present) Could (past) Could = possible action now or future (suggestion) Can (more sure) = Could (less sure) E.g. A: What shall we do this evening? B: We could go to the cinema. (suggestion)
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
E.g. When has Liz got to go? (or) When does Liz have to go?
Must mustn’t needn’t
Must it is necessary to do it
E.g. You must obey the school rules.
Mustn’t it is necessary not to do it
E.g. Students mustn’t smoke in the class.
Needn’t you don’t need to do it, but you can if you want
E.g. You can join with us but you needn’t join if you don’t want to.
Needn’t = doesn’t/don’t need
E.g. I needn’t to be angry. (or) I don’t need to be angry.
“Needn’t have done” is the past of “needn’t but they are completely different.
E.g. You needn’t write the notes down. It’s OK. (You don’t do it)
You needn’t have written the notes down. (but you did it)
“Didn’t need to (do)” and “Needn’t have (done)” are for the past tense form.
Didn’t need to (do) it’s not necessary and *I knew it* (so, I didn’t do it)
E.g. I didn’t need to get up early, so I didn’t.
Needn’t have (done) it’s not necessary and *I didn’t knew it* (so, I did it but I know it now) E.g. I needn’t have to get up early, but I did because I didn’t know it.
Should 1
Should It is good thing to do give
It is right thing to do *Advice or Opinion*
E.g. You look hungry. You should eat some food.
“Should we invite Susan to the party?” “Yes, I think we should.”
I think/I don’t think/Do you think + should:
E.g. I think my teacher should punish me.
Shouldn’t do something it isn’t a good thing to do:
E.g. I shouldn’t forgive him because he is guilty.
E.g. I am surprised that he should say such a thing.
If………. should………….
E.g. If it rains, we won’t go out.
We can use “Should” instead of “if”.
E.g. Should it rain, we won’t go out.
Should ……… / Should ………….: to give somebody “advice”
E.g. A: Shall I leave now?
B: No, I should wait a bit longer if I were you.
Had better It’s time…………
You’d better do something (give advice) there will be a problem or a danger if you don’t do it. E.g. We had better to stop for petrol soon. The tank is almost empty.
Negative form of “had better” is “had better not”. (had not better )
E.g. You don’t look very well. You had better not to go to work today.
For Spoken English: You’d better…. / I’d better…. Etc.
E.g. “Are you going out tonight?” “I’d better not. I’ve got a lot to do.”
Had better specific situation = should all types of situations
“had better” means that “there is always a danger of a problem if you don’t do it” but “should” means that “it
is a good thing to do”.
E.g. It is late. You’d better go. / You should go. (specific situation)
You’re always at home. You should go out more often. (general situation – not had better go)