1. My sister is cooking.
(-) My sister isn't cooking.
(?) Is your sister cooking?
2. They are 42 students in my class.
(-) They aren't 42 students in my class.
(?) Are they 42 students in your class?
3. We are reading books
(-) We aren't reading books.
(?): Are you reading books?
Ex 1 : Chuyển các câu sau sang phủ định và nghi vấn rồi trả lời theo gợi ý:
eg :
My father a polieman
( - ) My father a policeman.
( + ) My father isn't a policeman
( ? ) It your father a policeman ?
Yes, he is.