1. His German is very poor. He must (study/be studying/have studied) very hard. 2. His German is very good, he must (study/be studying/have studied) very hard. 3. His German is considerably improved, he must (study/be studying/have studied) hard during his holiday. 4. He must (study/be studying/have been studying) German these two years, his German is rather rich and fluent. 5. She must (have taken/be taking/have been taking) a bath at that moment that's why she did not answer your call. 6. She must (be/be being/have been) at home now, we saw her leaving the office. 7. She must (be/be being/have been) at home, she can't go away because there is no one to look after her sick mother. 8. You must always (think/be thinking/have thought) twice before you say anything. 9. Now he must (think/ be thinking/have thought) of what she has said. 10. He knows they are coming. They must (write/be writing/ have written) to him of their arrival in due time. 11. She must (play/be playing/have been playing) the piano now. 12. The foreigner must (understand/understood/have understood) me, for he nodded his head. 13. Where is Sara? I haven't seen her for a long time. – She must (stay/be staying/have stayed) at her friends'. She wanted to spend July with them. 14. He must (get/be getting/ have got) all he needed, otherwise he would have come again, 15. We must (meet/have met/have been meeting) somewhere before.
Exercise 3. Open the brackets and use the proper infinitive after the verb must
1. Look! All people in the street are going with their umbrellas up. It must (rain). 2. He has changed his job. He must (follow) your advice. 3. He must (fall) ill. Otherwise he would have come to the party. 4. Where is Michael? He must (be) here by now. – He lives in the country. He must (miss) the train. 5. What a dreadful noise! What is the matter? – Our neighbors must (quarrel) again. 6. Nobody must (notice) that he was not used to speaking in public. 7. The criminal must (be) very careful. He did not leave any fingerprints. 8. We are late, I am afraid. Ann must (wait) for us. 9. He must (forget) that he promised to come. 10. They must (write) a composition for two hours. They must (be) tired. 11. You must (misunderstand) me, I did not want to hurt your feelings. 12. Nobody must (see) him enter. Everybody started when he came in. 13. I hear someone’s steps outside. She must (go). 14. You may find him in the garden. He must (read). 15. It is impossible to change anything. One must (take) things as they are.
Exercise 4. Paraphrase the following sentences using the verb must
E x a m p l e: I am sure they have changed the time. –
They must have changed the time.
1. They are in Greece. I am sure they are enjoying themselves. 2. She is an experienced teacher. I am certain she has been working at school for at least twenty years. They have probably finished painting the house. 14. I feel sure she is at home. 5. Probably they have already passed the frontier. 6. She is sure he is playing cards with his friends. 7. She is not very young? As she seems to be. I think she is nearly forty. 8. I think you have visited this place before. 9. He has to do a very urgent task. I feel sure he is working now. 10. He is so absent-minded. I am sure he left the letter unanswered. 11. You know he is a good tennis player. He is no doubt has won this match. 12. I shan’t bother you any longer; no doubt you feel tired of my talking after a tiring day. 13. It is clear that they are expecting somebody. 14. She was obviously upset by something, I never saw her so nervous. 15. The youth is probably reading something funny. He is smiling all the time.