1.肯定句:表示"必须".must
You must wear uniforms on Mondays你们必须周一穿校服.
2.不定句:表示"禁止",mustn't You mustn't smoke你不准抽烟.
3.一般疑问句must提前
Must we wear uniforms every day?
我们必须每天穿校服吗?
肯定回答:Yes ,you muct,是的,你们必须否定回答:No,you needn't.不,你们不需要.
4.must表示推测"一定".
You must be thirsty after a long walk. 97我途步行之后你一定渴了.
Do型祈使句否定式
否定形式:Don't/Never+实义动词原形(+宾语+其他).
Don't run in the street. (不要在大街上乱跑.)
Don't eat in the classroom.(不要在教室里吃东西.)
Never do that again. (再也不要这么做了。)
Please don't get angry. (请不要生气.)
若句首有please
则在此后加don't