|在英文中，我们可以用have to来代替must，以下是have to的例子：
He has to go to Chicago tomorrow.（他明天应该去芝加哥）
They had to buy three tickets to go to the concert.（他们必须买三张票去听音乐会）
I have to work very hard.（我必须努力工作）
含有have to的句子，如要改成否定句子，必须在have to前面加do或它的变形，请看以下的例子：
He has to eat a lot of food. He does not have to eat a lot of food.
He had to leave. He did not have to leave.
I have to write that letter. I do not have to write that letter.
1. I saw your brother last night.
2. I like apples.
3. She is a beautiful girl.
4. They can play violin very well.
5. Mr. Chang must answer the following questions.
6. He went to see his brother last night.
7. He could sing many songs.
8. He will buy this car.
9. It rained heavily last night.
10. I have lived here for three years.
11. He has to see his mother.
12. He had to stay here yesterday.
6§2 No, Never和Any的用法
1.I saw no students here.
2.There are no lakes in this country.
3.I have no money.
4.I had no choice.
5.He has no friends.
1.I did not see any student here.
2.We can not find any lake in this country.
3.I do not have any money.
4.I did not have any choice.
5.He does not have any friends.
I have never gone there.
He has never written any song.
They have never washed their clothes.
1. I have money.
2. A selfish person does have any friends.
3. man is entirely alone.
4. one is living here. We can get into this house.
5. a single person loves me.
6. one loves me.
7. The person whom I saw did come.
8. I did go to work yesterday.
9. I had work to do yesterday.
10. I can find any one in this hall.
11. I have gone to America.
12. He has written to me.