The meanings of modal verbs and their equivalents

Function	Time	Form	Example
Ability	Present	can is/are able to	She can speak Spanish but she can’t speak Italian. Despite his handicap he is able to drive a car.
Past	could was/were able to	Mozart could play the piano at the age of five. Mike’s car broke down but he was able to repair it.
Possibility	Present	may might could	There may be a life on Mars. The rash could be a symptom of something more serious.
Past	could have might have	She might have done it; she had an opportunity and the motive.
Future	will be able to	We will be able to travel to the Moon.
Permission	Present/Future	can can’t	“Can I use your phone?” “No, I’m afraid you can’t”.
Past	was/were allowed to	I was allowed to leave early yesterday.
Obligation	Present	have to must need to should ought to	Students have to wear uniform. I must get up earlier. Do we need to get a visa for the USA? They really should/ought to consult shareholders first.
Past	had to	We had to report to Reception by four.
Future	will have to will need to	The Council will have to find ways of cutting costs next year.
Necessity	Present	must have to need to ought to	All human beings must/have to/need to have enough sleep.
Past	had to needed to	The staff and the students had to evacuate the campus.
Future	will have to will need to	You will have to/need to work harder than that.

A. These sentences come from an information booklet about a college. In each case choose the appropriate modal verb:may, must, can, should, be able to, or need .

1) The College welcomes part-time students who… work towards a qualification or attend a recreational education class.

2) Students claiming concessions for tuition fee payments … still pay the registration fees in full.

3) Late entries to examinations … be allowed, but will cost more than entering on time.

4) If you wish to attend a class in English for Speakers of Other Languages, you … take our test before you enroll.

5) If you need any advice, your first point of contact is your tutor, and you … always access other people through him or her.

6) A senior member of staff is on duty each evening between 6.30 and 9.30, and … be contacted via Reception.

7) Students attending evening classes only may not … access all our services. We … however make arrangements for you to see an appropriate adviser during the day.

8) It is regretted that people with physical disability … not be able to take the course that they choose.

9) The Student Council … be elected by students from across the college to represent and promote their general interests.

10) The College café is open from 8.30 am to 4 pm and from 5 to 8 pm. Outside these hours, a range of food and drinks … be purchased from vending outlets.

B. Choose the correct word or phrase to complete each sentence.

1) You must/needn’t save a file before you turn the computer off, or you will lose it.

2) I am afraid this is a non-smoking office, so you don’t have to/can’t smoke in here.

3) Employees are reminded that they mustn’t/needn’t use the office phone to make personal calls.

4) You needn’t/mustn’t send the reminder to Eastwood’s – they paid the invoice this morning.

5) In countries like Iran, you don’t have to/can’t buy or sell alcohol.

6) This income tax form must/needn’t be completed and returned to the Inland Revenue within 30 days.

7) You mustn’t/don’t have to come to the meeting if you have more important things to do.

8) This information is highly confidential, so you mustn’t/needn’t discuss it with anyone.

9) As you are from the European Union, you mustn’t/don’t have to have a visa to go to France.

10) Drivers wishing to hire a car must/can be over 21 and have a full driving license.

C. Look at the chart and make sentences using have to, don’t have to, or can’t.

	obligation	no obligation	prohibition
Airline pilots Union members University teachers Army officers Police officers	have good eyesight pay a subscription be graduates go to training courses be over 1.75m tall	work office hours be qualified teachers carry guns (UK)	drink before flying work during a strike go on strike

e.g. Airline pilots don't have to have excellent eyesight.

They don’t have to work office hours.

D. Change each of the following sentences using might, can’t, must, and a suitable infinitive.

1) It’s possible that they will give us the discount that we want.

They … might give us the discount we want.

2) Judging by the phone bill, I am sure she has been making long international calls.

Judging by the phone bill, she …

3) The factory is on a 3-day week. I am sure they aren’t selling many cars.

The factory is on a 3-day week. They…

4) It was a very bad deal. I am sure they lost a lot of money.

It was a very bad deal. They …

5) There is a chance she will be promoted at the end of the year.