can:----yes,you can
----no,you can't
may:----yes,you must
----no,you can't
must:做推测讲译为“一定”
---yes,he must
---no,he can't
做必须讲译为“必须”
---yes,you must
---no,you needn't
can't和musn't有什么区别:
can't
表示"不能够""不可以"和"不可能".如:
1.I cannot answer your question at present.我目前无法回答你的问题.
2.—Can I leave now 我可以走了吗
—No,I am afraid you can't.对不起,恐怕不行.
另外,cannot还用于固定习语中.如:
She cannot help laughing.她禁不住笑了.
I cannot but try again.我不得不再试一次.
You cannot be too careful.你越小心越好.
mustn't
表示" 不应该""不可以"和"禁止".如:
1.—May I take this book out of the reading room 我可以把这本书拿出阅览室吗
—No,you mustn't.不,不可以.
2.—Can I park my car here 我可以在这儿停车吗
—No,cars mustn't be parked here.不行,这里禁止停车.