Ability (can, could)
Five years ago, I (cannot/couldn't) play the piano.
Five years ago, I couldn't play the piano.
When I grow up, I (may/might) become an engineer.
When I grow up, I may become an engineer.
I think I (will/would) go to the beach this Sunday.
I think I will go to the beach this Sunday.
We have enough milk in the fridge so we (mustn't/needn't) buy some more.
We have enough milk in the fridge so we needn't buy some more.
(Can/Might) I play some music?
Can I play some music?
We (can/could) speak English well.
We can speak English well.
(Might/May) I have a glass of water?
May I have a glass of water?
I am feeling tired. I think I (would/will) go to sleep now.
I am feeling tired. I think I will go to sleep now.
Time is not on our side. We (must/need) hurry up.
Time is not on our side. We must hurry up.
(Could/Must) I have another coffee?
Could I have another coffee?
The volleyball team (can/could) go to the Olympics this year if they are lucky.
The volleyball team could go to the Olympics this year if they are lucky.
There is a small chance that we (may/might) go to the beach this weekend.
There is a small chance that we might go to the beach this weekend.
I (will/would) try to act like my father when I was young.
I would try to act like my father when I was young.
Mary gave me a letter to send. I (mustn't/needn't) forget to mail it.
Mary gave me a letter to send. I mustn't forget to mail it.
It (may/should/shouldn't) rain this evening.
It may rain this evening.
I (can't/couldn't) run that fast when I was six years old.
I couldn't run that fast when I was six years old.
If you leave the stove on, the house (may/might) catch on fire.
If you leave the stove on, the house might catch on fire.
If you get in trouble, I (will/would) help you.
If you get in trouble, I will help you.
You (mustn't/needn't) wash those carrots. They've already been washed.
You needn't wash those carrots. They've already been washed.
I (must/musn't/may) finish the report today.
I must finish the report today.
I think I (can/could) help you learn math if you study hard.
I think I can help you learn math if you study hard.
Billy and I (may/might) cook dinner tonight.
Billy and I may cook dinner tonight.
(Will/Would) you like steak or chicken?
Would you like steak or chicken?
He will be having lessons for another two hours. We (must/mustn't/need/needn't) visit him now.
He will be having lessons for another two hours. We mustn't visit him now.
Every car (must/could/couldn't/needn't) have seat belts.
Every car must have seat belts.