Both must and have got to can be used to talk about necessity. They are usually interchangeable; however, have got to is mainly used to talk about obligations that come from outside. On the other hand, must is mainly used to talk about the feelings and wishes of the speaker and the hearer. In American English, have to is more common than must.
Complete the following sentences using must or have (got) to.
1. I …………………. start dieting because I want to lose weight.
a) must
b) have got to
2. I ………………… start dieting because my boyfriend wants me to lose weight.
a) must
b) have got to
3. I …………………. get up early tomorrow. I have an interview at 9 am.
a) must
b) have got to
4. All candidates ………………… .. reach the examination hall before 10 am.
a) must
b) have got to
5. You …………………… obtain permission before building a house.
a) must
b) have got to
Answers
1. I must start dieting because I want to lose weight. (Here we are talking about the wishes of the speaker and hence must is used.)
2. I have got to start dieting because my boyfriend wants me to lose weight. (Here the obligation / necessity comes from outside.)
3. I must get up early tomorrow.
4. All candidates have to reach the examination hall before 10 am.
5. You have to obtain permission before building a house.
