情态动词：能力、请求与许可 · PET / B1
天天向上 · 原创语法学习讲义
根据对象和场合表达能力、许可、请求与帮助，兼顾礼貌和正确结构。
情态动词后用原形
can、could、may、would 等后面通常接动词原形，不加第三人称 -s。
She can organise the tickets for us.
她能为我们安排票务。
否定 can not 通常写成 cannot 或 can’t。
请求与许可的主语
Could you…? 请求对方行动；Can / Could / May I…? 询问自己是否可以行动。
Could you open the window? Could I open the window?
你能开窗吗？我可以开窗吗？
两个问题的行动者不同，要按意思选择 I 或 you。
could 不总表示过去
could 表过去一般能力，也可让现在的请求更委婉；would 可构成礼貌请求。
Would you help me fill in this form?
请你帮我填这张表，好吗？
would 后 help 用原形；Would you like to…? 用来邀请或询问意愿。
一般能力与一次成功
过去长期拥有的能力常用 could；某次克服困难成功做成某事，was / were able to 很常用。
Although the road was blocked, we were able to reach the village.
虽然道路堵塞，我们还是成功到达村庄。
不要把所有过去能力都机械改成 could；一次成功还可以用 managed to。
语境练习
1. You want a teacher to explain something again. Choose a polite request.
A. Could you explain it again, please?
B. You explained it again yesterday.
C. May I explain it again?
2. My brother can ___ simple websites.
A. to create
B. create
C. creates
3. When she was six, she ___ already read simple books.
A. could
B. can
C. may
4. You want permission to leave the room. Choose the suitable question.
A. May I leave the room?
B. Did I leave the room?
C. Could you leave the room?
5. An adult is carrying a heavy box. You offer help:
A. Would I to carry it?
B. Shall I carry it for you?
C. Shall we carried it yesterday?
6. “Could you email the plan tonight?” Here could expresses:
A. A polite request.
B. An ability the listener had only in childhood.
C. A completed action yesterday.
7. After trying three different routes, we finally ___ reach the campsite.
A. can
B. were able to
C. are able
8. Choose a correct invitation.
A. Would you like to join our team?
B. Would you like join our team?
C. Would you likes to join our team?
答案与解释
1. A · Could you explain it again, please?
请求老师行动用 Could you；May I 问自己是否可以。
2. B · create
情态动词 can 后用原形 create。
3. A · could
描述过去一般能力用 could。
4. A · May I leave the room?
请求自己离开的许可用 May I。
5. B · Shall I carry it for you?
Shall I + 原形表达提供帮助。
6. A · A polite request.
tonight 的请求语境说明 could 并非过去能力。
7. B · were able to
finally 和过去尝试说明一次过去的成功，were able to + 原形。
8. A · Would you like to join our team?
Would you like to + 原形用于邀请。
表达任务
给社团负责人写一封简短消息：介绍一种能力，礼貌请求一项信息，询问一个许可，并主动提供帮助。约 70–100 词。
□ 请求对方与请求许可的主语正确。
□ 情态动词后使用原形。
□ 礼貌表达与收件人、场合匹配。
参考表达
Hello Ms Green, I would like to help with the school festival. I can design posters and edit short videos. Could you tell me when the planning meeting takes place? May I bring a friend who is interested in photography? We could take pictures of the activities together. Shall I prepare a sample poster before the meeting? Thank you for your time. I look forward to hearing from you.
难度范围参照 Cambridge B1 Preliminary for Schools；本站原创练习，并非官方试卷。