Modals: Must, Have to, Need to, Don’t have to, Needn’t

Necessity or Requirement

Present and Future:

must / have to / need to + base form of the verb

1.    You must have a passport to cross the border.

2.    Elisabeth has to apply for her visa by March 10th.

3.    I need to drop by his room to pick up a book.

Past:

had to / needed to + base form of the verb

1.    I had to work late last night.

2.    I needed to drink a few cups of coffee in order to stay awake.

Note: have to and need to are often used in the same context, but many times, need to is used to express something that is less urgent, something in which you have a choice.

Almost 100% Certain

must + base form of the verb

1.    Thomas has lived in Paris for years. His French must be very good.

To Persuade

must / have to + base form of the verb

1.    You must try this wine. It’s excellent.

2.    You have to visit us while you’re in town.

Prohibited or Forbidden

must not / mustn’t + base form of the verb

1.    You must not drive over the speed limit.

2.    You mustn’t leave medicines where children can get to them.

Lack of Necessity

don’t /doesn’t /didn’t + have to + base form of the verb

1.    You don’t have to park the car. The hotel valet will do it for you.

2.    Tim doesn’t have to go to school today. It’s a holiday.

3.    You didn’t have to shout. Everyone could hear you.

needn’t + base form of the verb

1.    You needn’t worry about me. I’ll be fine.

Exercises: Must, Have to, Need to, Don’t Have to, Needn’t

Fill in the blanks with one of these modals:
must, must not, have to, has to, don’t have to, doesn’t have to, needn’t as in the examples.
There may be more than one correct answer.

1.    Shira doesn’t have to drive to the airport. She’s going by taxi.

2.    You must speak politely to the customers.

1.    You ______ tell Anna about the party tomorrow night. It’s a surprise! (must not, need to, doesn’t have to)

2.    Tina _______ register for her classes on Monday, otherwise she won’t get a place in them. (doesn’t have to, mustn’t, has to)

3.    You ________ send that fax. I’ve already sent it. (must, will have to, don’t have to)

4.    A dog ______ get special training in order to be a guide dog. (must, need to, don’t have to)

5.    Jeremy _______ get up early tomorrow. His class was cancelled. (mustn’t, doesn’t have to, don’t need to)

Answers:

1.    must not

2.    has to

3.    don’t have to

4.    must

5.    doesn’t have to