3. Tom often helps us. (对划线部分提问)

　　 　　 often 　　 you?

2. We have finished the work. (改为一般疑问句)

　 　　　 you 　　 the work?

疑问句可分为一般疑问句、特殊疑问句、选择疑问句和反意疑问句。

[练习导航]

Ⅰ. 按要求完成下列句子，每空一词。

1. He is an English teacher. (改为一般疑问句)

　　 　　 　　 an English teacher?

10. There will be a lot of tourists to our city in the future.

　　 　　 　　 be a lot of tourists to our city in the future.

[指点迷津]

肯定句变为否定句时要注意以下几点：

◆含有be动词、助动词、情态动词的肯定句变为否定句时，直接在上述动词后加not。其中，must作“必须”讲时，其否定形式应为don’t have to或needn’t。

◆含有行为动词的肯定句变为否定句时，要根据相应的人称和时态，借助助动词do / does / did +not来构成。

9. We use plastic bags when shopping.

　　 We 　　 　　 plastic bags when shopping.

8. Grace learns English by reading aloud.

　　 Grace 　　 　　 English by reading aloud.

7. The office building is next to the hotel.

　　 The office building 　　 next to the hotel.

6. Lucy seems to be sad.

　　 Lucy 　　 　　 to be sad.

5. She came here last week.

　　 She 　　 　　 here last week.

4. Sara is washing dishes in the kitchen.

　　 Sara 　　 　　 dishes in the kitchen.