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。