Have to (in its correct form). Sometimes it is possible to use either; sometimes only have to is possible. Examples: Well, it's 10 o'clock. I must (or have to)... go now. Ann was feeling ill last night. She had to leave the par...

Have to (in its correct form). Sometimes it is possible to use either; sometimes only have to is possible. Examples: Well, it's 10 o'clock. I must (or have to)... go now. Ann was feeling ill last night. She had to leave the party early. 1 You really......................... work harder if you want to pass that examination. 2 Many children in Britain......................... wear uniform when they go to school. 3 Last night Don suddenly became ill. We........................ call the doctor. 4 Ann has......................... wear glasses since she was eight years old. 5 I'm afraid I can't come tomorrow. I....................... work late. 6 I'm sorry I couldn't come yesterday. I...................... work late. 7 Tom may.......................... go away next week. 8 We couldn't repair the car ourselves. We....................... take it to a garage. 9 When you come to London again, you1....................................... come and see us.