1. be动词(am/is/are)

主语 be动词(原形) be动词(过去式)

I am was He/she/it is was

We/you/they are were

2.助动词(do/does/did)

问句 答句

Do+非第三人称单数

+动词原形…?

…do/don’t

Does+第三人称单数

…does/doesn’t

Did+所有主格

…did/didn’t

问句 答句

What do you/they/we…

+动词原形?

I/They/We+动词原形…。

What does he/she/it…

He/She/It +(动词+S)….

What did you/they/we/ he/she/it…

I/They/We/ He/She/It +动词过去式。