以下是针对16个常见情态动词（can, could, may, might, must, shall, should, will, would, ought to, need, dare, used to, had better, have (got) to, be able to）的肯定句、否定句和疑问句的举例：
1. can
肯定句: I can swim.
否定句: I cannot swim. 或 I can't swim.
疑问句: Can you swim?
2. could
肯定句: She could play the piano when she was five.
否定句: She couldn't play the piano when she was five.
疑问句: Could he play the guitar?
3. may
肯定句: You may borrow my book.
否定句: You may not borrow my book.
疑问句: May I use your phone?
4. might
肯定句: They might come tonight.
否定句: They might not come tonight.
疑问句: Might she know the answer?
5. must
肯定句: You must finish your homework.
否定句: You mustn't talk in class.
疑问句: Must I hand in my report today? （回答可以是Yes, you must. / No, you don't have to.）
6. shall
肯定句: We shall meet at the gate at eight.
否定句: We shall not meet at the gate at eight.
疑问句: Shall we go for a walk?
7. should
肯定句: You should eat more vegetables.
否定句: You shouldn't stay up late.
疑问句: Should they call him back?
8. will
肯定句: He will arrive tomorrow.
否定句: He will not arrive tomorrow. 或 He won't arrive tomorrow.
疑问句: Will she pass the exam?
9. would
肯定句: They would like some coffee.
否定句: They wouldn't like any tea.
疑问句: Would you prefer a cup of tea?
10. ought to
肯定句: You ought to apologize to her.
否定句: You ought not to lie.
疑问句: Oughtn't we to help them? （较少见，更常用Should we...？）
11. need
肯定句: You need to rest.
否定句: You needn't worry about it.
疑问句: Need I buy another ticket? （回答可以是Yes, you do. / No, you don't.）
12. dare
肯定句: He dares to tell the truth.
否定句: He doesn't dare to tell the truth.
疑问句: Dare she speak in front of everyone?
13. used to
肯定句: I used to play tennis every weekend.
否定句: I didn't use to play tennis every weekend.
疑问句: Did you use to collect stamps?
14. had better
肯定句: You had better study harder.
否定句: You had better not miss the meeting.
疑问句: Hadn't we better leave early?
15. have (got) to
肯定句: I have to go now.
否定句: I don't have to finish it today.
疑问句: Do you have to wear a suit?
16. be able to
肯定句: She will be able to finish the project on time.
否定句: He wasn't able to come to the party.
疑问句: Will they be able to find the address?
这些例子展示了如何在不同的句子结构中使用情态动词来表达肯定、否定和疑问的意义。
