1) You seem to be having trouble there. Can I help you? (may - более формальный стиль)
2) Hello, May I speak to Mary, please?
3) I don't have enough money to buy lunch. Could you lend me a couple of dollars?
4) Professor Villa, we've finished our work for today. May we leave now, please?
5) Could you please try to be nicer to your brother?
6) May I come in?
7) Could you please tell me what time it is.
8) Не указано подлежащее: если I или we, то Can I speak German?, если you, то could you speak German?
9) Sorry, but could you lend me some money?
10) You may go for a walk if you have done all the exercises.
1) Where’s your friend? — Не must be in New Уоrк. He was going to visit his friends. (утверждение, основанное на факте)
2) Where is Nick? He might be in his office. I’m not sure. (вероятность, не подкрепленная фактом)
3) The sky is quite clear. I don’t think it must rain. (уверен)
4) You’ve been reading all day. You might be tired. (возможный домысел)
5) What is your brother doing now? – I don’t know. He might be playing the computer games. (возможный домысел)
6) According to your behavior, you might be in love. (возможный домысел, поскольку первая часть предложения не всегда является следствием второй части)
7) Tom and Rebecca give their daughter a lot of presents. They must really love her. (really говорит сам за себя)
8) – Why is Anna absent?
- God knows! She might be ill.(лишь догадка)
9) – Nobody answers.
- They must be working in the garden. They told mе yesterday that they were going to do it. (уверенность в первом предложении придает факт намерения во втором предложении)
10) Look at those dark clouds! I’m sure it must rain. (sure говорит об уверенности того, кто говорит, соответственно must)