Unit 6 Electricity知識點整理
1) must(“必須”, 表示命令)，mustn’t(“一定不能”, 表示強烈禁止...)
如：you must go to bed before 22:00pm.
you mustn’t play with fire. it’s dangerous!
--must i write down the sentences？
--no，you needn’t. (--no, you don’t have to)
注意：在回答must的疑問句中，否定回答用needn’t或don’t have to表示“不必”，不用mustn’t
2) must 還可以表示非常肯定的猜測，意為“一定”
如：the girl in a red skirt must be lucy.
3) must/ have to 的區別：
①. must表示必須，強調主觀上的愿望；have to表示“不得不”，強調客觀需要
如：you must go be bed before 22:00pm. my bike is broken, so i have to go to school on foot.
②. have to 有人稱、數、時態的變化；must則沒有。
如：i have to clean the classroom today. she has to finish her homework first.
it was late, he had to go to school without breakfast.