现在进行时态的结构是
助动词be +doing
一般疑问句是直接把
be动词提到句子开头
否定句是直接在be后加 not
特殊疑问句是 疑问词加一般疑问句
如
He is doing his homework .
他正在做作业。
一般疑问句是
Is he doing his homework?
他正在做作业吗?
特殊疑问句是
What is he doing?
他正在做什么?
又如
They are cleaning the floor.
他们正在打扫地板。
一般疑问句是
Are they cleaning the floor?
Yes, they are.或 No, they aren't.
特殊疑问句是
What are they doing?
他们在做什么?
或
Who is cleaning the floor?
谁在打扫地板?