must的后面加动词什么形式?

must 是情态动词.所以要接动词原形了
如:
The teacher said,"You must get back before 10 o'clock."
----The teacher said that we must get/go back before 10 o'clock.
虽然must 在两个句中的时态不同,但作为情态动词must可以用语各种时态,形式不变.

must 是情态动词.所以要接动词原形了
如:
The teacher said,"You must get back before 10 o'clock."
----The teacher said that we must get/go back before 10 o'clock.
虽然must 在两个句中的时态不同,但作为情态动词must可以用语各种时态,形式不变.

看情况而定
1.动词原行
2.当用玩成时的时候，后面可以接have done。

加原形 HAVE DONE 中的HAVE也是原形

must "do"
must " have done/been"
must "be"