Have to (in its correct form). Sometimes it is possible to use either; sometimes only have to is possible. Examples: Well, its 10 oclock. 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 Im afraid I cant come tomorrow. I....................... work late. 6 Im sorry I couldnt come yesterday. I...................... work late. 7 Tom may.......................... go away next week. 8 We couldnt repair the car ourselves. We....................... take it to a garage. 9 When you come to London again, you1....................................... come and see us.

1 You really .have to.. work harder if youwant to pass that examination.
2 Many children inBritain..have to... wear uniform when they go to school.
3Last night Don suddenly became ill. We..had to... call thedoctor.
4 Ann has...had to.. wear glasses since she waseight years old.
5 Im afraid I cant come tomorrow.I..have to... work late.
6 Im sorry I couldnt comeyesterday. I..had to... work late.
7 Tommay..have to... go away next week.
8 We couldnt repairthe car ourselves. We..had to.. take it to a garage.
9 Whenyou come to London again, you  must.......come and see us.