什么情况下be是不用变成am is are was were 的

什么情况下be是不用变成am is are was were 的
什么情况下be是不用变成am is are was were 的

什么情况下be是不用变成am is are was were 的
和 情态动词can, must,may ,will,would等等连用时,用be动词原形
比如,He may be right 他可能是对的

有些词是后面要加动词原形，如must may ....,不用变am is are

跟在情态动词后面时用BE。

1.动词不定式后面如：I want to be a doctor.
2.情态动词后，如：can,may,could,shall.should.
3祈使句中：Don't be late.Be careful.