# 情態動詞的否定
情態動詞+not+動詞原形
```
He can't sing an English song.
He may not know her.
He mustn't go there.
He doesn't have to go there.
```
# 情態動詞的提問
情態動詞+主語+動詞原形
```
Can he sing a English song?
-Yes,he can./No,he can't.
Must he go there?
Yes,he must./No,he needn't.
Does he have to go there?
Yes,he does./No,he doesn't.
```
