一般现在
He is a boy
He is not crazy
Is Lily here?
一般过去
She was late yesterday
She was not here yesterday
Was him here yesterday?
现在进行
She is crying
He is not listening
What are you doing?
一般将来
I will take it
She will not come
Will you be there?
现在完成
I've finished my homework
I have not finished
Have you finished your work?
情态动词
I can do it
She might not come
Would you like come?