a)
+ I'm doing my homework now.
- I'm not doing my homework now.
? Are you doing your homework now?
b)
+ You cleaned the room yesterday.
- You didn't clean the room yesterday.
? Did you clean the room yesterday?
c)
+ She has already helped her mother.
- She hasn't helped her mother yet.
? Has she helped her mother yet?
d)
+ Tom often goes to the park.
- Tom doesn't often go to the park.
? Does Tom often go to the park?
