Modals

Modal verbs and their meaning

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What are modal verbs?

Modals (also called modal verbs, modal auxiliary verbs, modal auxiliaries) are special verbs which behave irregularly in English. They are different from normal verbs like "work, play, visit..." They give additional information about the function of the main verb that follows it. They have a great variety of communicative functions.
Here are some characteristics of modal verbs:

• They never change their form. You can't add "s", "ed", "ing"...
• They are always followed by an infinitive without "to" (e.i. the bare infinitive.)
• They are used to indicate modality allow speakers to express certainty, possibility, willingness, obligation, necessity, ability

List of modal verbs

Here is a list of modal verbs:

can, could, may, might, will, would, shall, should, must

The verbs or expressions dare, ought to, had better, and need not behave like modal auxiliaries to a large extent and my be added to the above list

Use of modal verbs:

Modal verbs are used to express functions such as:

1. Permission
2. Ability
3. Obligation
4. Prohibition
5. Lack of necessity
6. Advice
7. possibility
8. probability

Examples of modal verbs

Here is a list of modals with examples:

Modal Verb	Expressing	Example
must	Strong obligation	You must stop when the traffic lights turn red.
	logical conclusion / Certainty	He must be very tired. He's been working all day long.
must not	prohibition	You must not smoke in the hospital.
can	ability	I can swim.
	permission	Can I use your phone please?
	possibility	Smoking can cause cancer.
could	ability in the past	When I was younger I could run fast.
	polite permission	Excuse me, could I just say something?
	possibility	It could rain tomorrow!
may	permission	May I use your phone please?
	possibility, probability	It may rain tomorrow!
might	polite permission	Might I suggest an idea?
	possibility, probability	I might go on holiday to Australia next year.
need not	lack of necessity/absence of obligation	I need not buy tomatoes. There are plenty of tomatoes in the fridge.
should/ought to	50 % obligation	I should / ought to see a doctor. I have a terrible headache.
	advice	You should / ought to revise your lessons
	logical conclusion	He should / ought to be very tired. He's been working all day long.
had better	advice	You 'd better revise your lessons

Remember

Modal verbs are followed by an infinitive without "to", also called the bare infinitive.

Examples:

• You must stop when the traffic lights turn red.
• You should see to the doctor.
• There are a lot of tomatoes in the fridge. You need not buy any.

Grammar Exercise - Modals

Choose the right modal verb

1. There are plenty of tomatoes in the fridge. You                               mustn't               needn't               may not               should not              buy any.
2. It's a hospital. You                               mustn't               needn't               may not               don't have to              smoke.
3. He had been working for more than 11 hours. He                               must               need               had better               mustn't                be tired after such hard work. He                               may               should               must               had better              prefer to get some rest.
4. I                               could               might               can               must              speak Arabic fluently when I was a child and we lived in Morocco. But after we moved back to Canada, I had very little exposure to the language and forgot almost everything I knew as a child. Now, I                               may               can               must               need              just say a few things in the language.
5. The teacher said we                               can               needn't               must               should              read this book for our own pleasure as it is optional. But we                               could               need               needn't               mustn't              read it if we don't want to.
6.                               May               Need               Must               Can              you stand on your head for more than a minute? No, I                               may not               needn't               can't              .
7. If you want to learn to speak English fluently, you                               could               need               needn't               mustn't              to work hard.
8. Take an umbrella. It                               need               should               mustn't               might              rain later.
9. You                               shouldn't               need               needn't               may not              leave small objects lying around . Such objects                               must               need               may               mustn't              be swallowed by children.
10. People                               couldn't               needn't               mustn't               may not              walk on grass.
11. Drivers                               could               must               may              stop when the traffic lights are red.
12.                               May               Must               Should               Will              I ask a question? Yes, of course.
13. You                               couldn't               needn't               mustn't               may not               take your umbrella. It is not raining.
14.                               Can               Need               Should               May              you speak Italian? No, I                               shouldn't               mustn't               may not               can't              .

Modals in the present and past

Generally speaking modals in the past have the following form:

• modal + have + past participle

Example:

• Present:
  You should see a doctor.
• Past:
  You should have seen a doctor

Except for modals that express obligation,ability and lack of necessity:

• Obligation:
  Present = I must / have to work hard. -- Past = I had to work hard.
• Ability:
  Present = I can run fast. -- Past = I could run fast when I was young.
• Lack of necessity:
  Present = You don't have to / needn't take your umbrella. -- Past = You didn't have to / didn't need to take your umbrella.

	Modals in the Present	Modals in the Past
Obligation	You must / have to stop when the traffic lights are red.	You had to stop.
Advice	You should see a doctor.	You should have seen a doctor
Prohibition	You mustn't smoke here.	You mustn't have smoked there.
Ability	I can run fast.	I could run fast. now I am old.
Certainty	He has a Rolls Royce. He must be very rich. He can't be American. His English is terrible.	He must have been rich. He had a big house and an expensive car. He can't have written that poem. He was illiterate.
Permission	Can I go out?	She could drive her father's car when she was only 15.
Possibility	It may / can / could / might rain. It's cloudy.	I guess it may / can / could / might have been Lacy on the phone.
Lack of necessity	You don't have to / needn't buy any tomatoes. There are plenty in the fridge.	You didn't have to / didn't need to buy tomatoes.

Must and Have to

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What's the difference between must and have to?

Must and have to are modal verbs in English. This page will guide you to the proper use of these modals.

Must

1. We use must to make a logical deduction based on evidence. It indicates that the speaker is certain about something:
Examples:

• It has rained all day, it must be very wet outside.
• The weather is fantastic in California. It must a lot fun to live there.

2. Must is also used to express a strong obligation.
Examples:

• Students must arrive in class on time.
• You must stop when the traffic lights are red.
• I must go to bed.

Have to

Like must, have to is used to express strong obligation, but when we use have to there is usually a sense of external obligation. Some external circumstance makes the obligation necessary.
Examples:

• I have to send an urgent email.
• I have to take this book back to the library.

Shall and Will

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What is the difference between shall and will?

Shall is not used often in modern English especially in American English. In fact, shall and will have the same meaning and are used to refer to the simple future. They are use as follows:

• will is used with all persons
  

  I, you, he, she, it, we, they	will	go there

• shall is used with the first person singular and plural
  

  I, we	shall	go

• The short form of will and shall is 'll

  I, you, he, she, it, we, they	will or 'll	call you

  
  

  I, we	shall or 'll	call you

• In the negative, the short forms of will not and shall not are won't and shan't respectively
  

  I, you, he, she, it, we, they	won't	give up

  
  

  I, we	shan't	give up

Uses of shall

It should be noted that shall is often used to make suggestions, offers or ask for advice. It is used in questions as follows:

• Shall we stay or go out?
• Shall we dance?
• Shall I get his phone number if I meet him?
• What shall I do to get rid of my acne?

As said above shall is used with first person singular and plural (I and we.) But there is a very special use of shall with other persons to make a promise, command or threat as noted below:

• You shall not get in! (Command)
• You shall pay for it. (Threat)
• You shall get your money back soon. (Promise)

In American English shall is mainly used in formal or legal documents:

• You shall abide by the law.
• There shall be no trespassing on this property.
• Students shall not enter this room.