The modal auxiliary verbs are: will/shall, can/could, may/might, must, ought to, would, should.

19.1 Usage: Will/Shall:

Will/shall are used:

A: to construct the Future Tense of regular and irregular verbs.

e.g. My parents will visit Strasbourg next week.

B: to show that a decision has been made:

e.g. I will buy a new car on Friday.

C: to show that a promise, offer or invitation exists:

e.g. My uncle said that he will drive me to your house this evening. - promise

Will you come to England with me? - invitation

D: to make an urgent request, to give an order:

e.g. Will you come to my house immediately, please? - request

John, you will pay for the tickets, now! - order

E: to make a suggestion/offer in the form of a question:

e.g. Shall we buy tickets for the concert? - suggestion

Shall I help Derek to repair the car - offer

19.2 Usage: Can/Could:

A: to describe ability/willingness to do something now or in the past.:

e.g. Bill can drive a car very well. - ability

Marcel can play the piano at the party - willingness now

My parents could play golf twenty years ago - ability past

Bill could take photographs until he lost his camera - willingness past

B: to give an explanation or ask for permission:

e.g. In England, you can drive a car at the age of seventeen. - explanation

Can Mary use your computer, this evening?

C: to express perception with certain verbs by using can in the present tense, and could in the past tense. The verbs are: to feel, hear, see:

e.g. Bill and Mary can see the River Seine from their house.

Derek could hear the church bells every Sunday morning when he lived in Milan.

Ann can feel the heat of the sun before she sees it.

D: to explain a possibility and to make a suggestion in the present and future tenses by using could:

e.g. The old table could be in the garage - present

We could go to the cinema next Sunday - future

Could Mary help you to make this dress? - present

19.3 Usage: May/Might:

A: to express a possibility/make a suggestion at the present time or in the future. The equivalent in French is peut-être:

e.g. If you return tomorrow, you may see Mr Smith.

If you return tomorrow, you might see Mr Smith.

It may rain on Thursday or it might snow.

N.B. Might suggests less certainty than may.

B: to give/ask for permission by using may:

e.g. The workers may leave at six o'clock if they have finished their work. - give permission

May I see you tomorrow? - ask permission

19.4 Usage: Must:

A: to explain obligation or necessity where there is no choice: must is used with the Simple Present and Future Tenses:

e.g. You must buy a ticket to use the train - obligation

To succeed, Mary must work harder at school. - necessity

N.B. Have to + infinitive: Have got to + infinitive have the same meaning as must:

e.g. To succeed, Mary has to work harder at school.

To succeed, Mary has got to work harder at school.

B: to assume knowledge of a fact or information now - use must:

to assume knowledge of a fact or information in the past - use must have:

e.g. Martin must like his job, he has worked in that office for ten years. - now

The roads are wet, it must have rained last night. - past

19.5 Usage: Ought to:

A: to express an obligation and to give advice that may be refused or accepted::

e.g. Europeans ought to send food to poor African countries.

We ought to leave early to catch the first train of the day.

N.B. Ought to has the same meaning as should:

e.g. Europeans should send food to poor African countries.

We should leave early to catch the first train of the day.

19.6 Usage: Would:

A: to describe or talk about a situation/activity that is imagined or thought about:

e.g. I would like to visit Canada soon.

My parents would know all about the British Museum in London.

B: to ask for or supply factual information:

e.g. If you would permit me, I can show you the way to Notre Dame.

Would you please tell me the price of a ticket to the museum.

C: to issue or accept an invitation:

e.g. Would you like to come to New York with me?

My parents would like to meet your parents as soon as possible.

D: to explain a preference:

e.g. Bill would drink tea and Mary would prefer coffee.

Would Jane eat fish if I cooked it well?

E: to report events, activities, situations, facts in the past which were first expressed using will and in Direct Speech:

e.g. original words: The teacher said, " I will be late to lessons tomorrow."

reported words: The teacher said that he would be late for lessons the next day.

F: to offer advice when there is a choice:

e.g. If I was you, I would go home now.

Would you like a banana or an apple?

G: to offer choice in the form of a question:

e.g. Would you like a banana or an apple?

Would your parents like to come here for a holiday?

19.7 Usage: Should:

A: to express an obligation or necessity where there is a choice:

e.g. The old man should see a doctor about his injury. ( but he may choose not to )

University students should work very hard. ( but they may choose not to )

B: to express thoughts and personal opinions aloud:

e.g. I think Brian should find a job now.

John should tell Beatrice his plans.

N.B. In every case, Should has the same meaning as ought to:

19.8 Structure: Modal Auxiliary Verbs:

A: The basic form is modal auxiliary verb + infinitive without to:

e.g. Mary may walk home after walk.

William ought to lose weight.

B: Modal auxiliary verbs always have the same form in all tenses: will/shall, can/could, may/might, must, ought to, would, should.:

e.g. I may see you this morning. - present

Bill chose the moment when he would explain his idea. - past

Mary ought to go to work tomorrow. - future

C: The modal auxiliary verb + perfect infinitive is used to describe an event, activity or situation that may/may not have happened in the past:

e.g. The teacher ought to have warned me about this possibility .

It might have rained in the desert two years ago.

D: The Modal Auxiliary Verb + be + the infinitive ending -ing is used to talk about obligation or possibility in the present and future tense:

e.g. Usually, I would be working but today is a public holiday. - present

Next week, Elizabeth ought to be flying to Washington. - future

E: Like all auxiliary verbs, Modal Auxiliary Verbs are used in Question Tags:

e.g. You can come with me, can't you?

You wouldn't tell her, would you?

19.9 Structure: Negatives:

In negative statements, modal auxiliary verbs have not or n't after them:

e.g. positive statement: Mary cannot go to the library this morning.

negative statement: /Mary can't go to the library this morning.

positive statement: You should clean your car every day.

negative statement: /You shouldn't clean your car every day.

19.10 Structure: Negatives: Exception:

A: Use must not or mustn't where there is an obligation/necessity and no choice:

e.g. positive statement: In England, you must drive your car on the left.

negative statement: In France, you must not drive your car on the left.

/In France, you mustn't drive your car on the left.

B: Use need not or needn't where there is an obligation or necessity and a choice:

e.g. positive statement: Children ought to visit your parents each week.

negative statement Children need not visit their parents each week.

/Children needn't visit their parents each week.

19.11 Structure: Questions:

In questions, the Modal Auxiliary Verb comes before the subject:

MV S V

e.g. May I offer you a cup of tea?

QW MV S V

e.g. When will you know the result of the examination?