Grammar Rules
Modal Verbs
Modal and Modal Phrases (Semi-Modals)
A modal is a type of auxiliary (helping) verb that is used to express: ability, possibility, permission or obligation. Modal phrases (or semi-modals) are used to express the same things as modals, but are a combination of auxiliary verbs and the preposition to. The modals and semi-modals in English are:
- Can/could/be able to
- May/might
- Shall/should
- Must/have to
- Will/would
Can, Could, Be Able To
Can, could and be able to are used to express a variety of ideas in English:
Ability/Lack of Ability
Present and Future:
can/can't + base form of the verb- Tom can write poetry very well.
- I can help you with that next week.
- Lisa can't speak French.
- Mike is able to solve complicated math equations
- The support team will be able to help you in about ten minutes.
- I won't be able to visit you next summer.
Past:
could / couldn’t + base form of the verb- When I was a child I could climb trees.
- I wasn't able to visit her in the hospital.
- He hasn't been able to get in touch with the client yet.
- Incorrect: I can to help you this afternoon.
- Correct: I can help you this afternoon.
- Correct: I will (I'll) be able to help you this afternoon.
Possibility / Impossibility
can / can't + base form of the verb- You can catch that train at 10:43.
- He can't see you right now. He’s in surgery.
- I could fly via Amsterdam if I leave the day before.
Ask Permission / Give Permission
Can + Subject + base form of the verb (informal)- Can you lend me ten dollars?
- You can borrow my car.
- Could I have your number?
- Could I talk to your supervisor please?
Make a suggestion - To make a suggestion use:
Could + base form of the verb (informal)- You could take the tour of the castle tomorrow.
Exercises: Can, Could, Be able to
Fill in the correct form of can, could or be able to as in the examples.
- Ben could not help his little brother with his homework yesterday.
- Can I call you later tonight?
- _______ Tony run long distances when he was a boy?
- ______ you please call a tow truck for me? My car broke down. (polite)
- The students _______ to buy their textbooks today. The bookstore is all out of them.
- ______ you teach me how to fix my computer? You’re so good at it.
- ______ you ______ reach the customer if you call him at 4:00 his time?
- Could
- Could
- aren't able
- Can
- Will/be able to
May, Might
Formal Permission / Formal Prohibition
may / may not + base form of the verb- You may start your exam now.
- You may not wear sandals to work.
Polite Request
May + subject + base form of the verb- May I help you?
Possibility / Negative Possibility
may/ might + base form of the verb- We may go out for dinner tonight. Do you want to join us?
- Our company might get the order if the client agrees to the price.
- Adam and Sue may not buy that house. It's very expensive.
- They might not buy a house at all.
To Make a Suggestion (when there is no better alternative)
may as well / might as well + base form of the verb- You may as well come inside. John will be home soon.
- We might as well take Friday off. There’s no work to be done anyway.
Polite Suggestion
might + base form of the verb- You might like to try the salmon fillet. It's our special today.
Exercises: May / Might
Fill in the correct form of may or might as in the example.
- May I sit here?
- They ______ finish the project on time. The main engineer is ill.
- You _____ want to stop by the museum gift shop on your way out.
- _____ I have your autograph?
- He _______ visit the Louvre. He’s in Paris anyway.
- You ______ park your car here. It’s reserved for guests of the hotel only.
- might not
- might
- May
- may as well
- may not
Shall, Should, Ought to
To Offer of Assistance or Polite Suggestion (When you are quite sure of a positive answer)
Shall + subject + base form of the verb- Shall we go for a walk?
To Offer of Assistance or Polite Suggestion (When you are not sure of a positive answer)
Should + subject + base form of the verb- Should I call a doctor?
A Prediction or Expectation that Something Will Happen
should/shouldn’t + base form of the verb- The proposal should be finished on time.
- I shouldn't be late. The train usually arrives on time.
To Give Advice
should / ought to + base form of the verb- You should check that document before you send it out.
- You ought to have your car serviced before the winter.
To Give Advice (about something you think wrong or unacceptable)
shouldn’t + base form of the verb- James shouldn't teach him words like those.
Exercises: Should, Shouldn’t, Ought To
Fill in should, shouldn’t or ought in the following sentences as in the example.
- He shouldn't encourage such bad behavior.
- You _____ get your teeth cleaned at least once a year.
- The house ______ be ready to move into by next month. It’s almost finished.
- Ron ________ to improve his attitude. If he doesn’t, he might get fired.
- ________ I get your jacket? It’s cold in here.
- You ________ put your feet on the table. It’s not polite.
- should
- should
- ought
- shall
- shouldn't
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- You must have a passport to cross the border.
- Elisabeth has to apply for her visa by March 10th.
- I need to drop by his room to pick up a book.
Past:
had to / needed to + base form of the verb- I had to work late last night.
- I needed to drink a few cups of coffee in order to stay awake.
Almost 100% Certain
must + base form of the verb- Thomas has lived in Paris for years. His French must be very good.
To Persuade
must / have to + base form of the verb- You must try this wine. It’s excellent.
- You have to visit us while you’re in town.
Prohibited or Forbidden
must not / mustn’t + base form of the verb- You must not drive over the speed limit.
- 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- You don't have to park the car. The hotel valet will do it for you.
- Tim doesn't have to go to school today. It’s a holiday.
- You didn't have to shout. Everyone could hear you.
- 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.
- Shira doesn't have to drive to the airport. She’s going by taxi.
- You must speak politely to the customers.
- You ______ tell Anna about the party tomorrow night. It's a surprise! (must not, need to, doesn't have to)
- Tina _______ register for her classes on Monday, otherwise she won't get a place in them. (doesn't have to, mustn't, has to)
- You ________ send that fax. I've already sent it. (must, will have to, don't have to)
- A dog ______ get special training in order to be a guide dog. (must, need to, don't have to)
- Jeremy _______ get up early tomorrow. His class was cancelled. (mustn't, doesn't have to, don't need to)
- must not
- has to
- don't have to
- must
- doesn't have to
Modals: Will / Would
will / won't + base form of the verb
- John will pick you up at 7:00am.
- Beth won't be happy with the results of the exam.
Polite Request or Statement
Will / Would + base form of the verb- Will you please take the trash out?
- Would you mind if I sat here?
- I'd (I would) like to sign up for your workshop.
Habitual Past Action
Would/Wouldn't + base form of the verb- When I was a child, I would spend hours playing with my train set.
- Peter wouldn't eat broccoli when he was a kid. He loves it now.
Exercises: will, would
Fill in the blanks with one of the following words: will, won't, would, wouldn't.
- Will you please help me lift this box?
- I ______ like to order the onion soup please.
- The manager _______ be pleased to hear that a customer slipped on the wet floor.
- _______ it be okay if I slept here tonight?
- When Igor lived in Russia, he ________ call his mother as often as he does now.
- I can assure you sir, the order ______ be shipped out tonight.
- would
- won't
- would
- wouldn't
- will
Exercises – All Modals
Fill in the blanks with the correct form of the following modals:
can, could, be able to, may, might, shall, should, must, have to, don't have to, need to
- You may have to make the modals negative according to the context of the sentence.
- There may be more than one possibility.
- He has to take his car to be serviced. The brakes are squeaking.
- Would you please save me a seat at the dinner event.
- If you are sick, you ________ go to work. You'll infect everyone there.
- Drivers _______ stop at red lights.
- You _______ finish the proposal today. You can finish it tomorrow.
- She ______ hear much better with her new hearing aids.
- ______ I order us a bottle of wine?
- Sam ______ pick his daughter up from school. She's taking the bus home.
- You _____________ smoke here. It's a smoke-free building.
- You ________ eat so many sweets. They are bad for you.
- _________ you mind walking a little faster? We're going to be late.
- I'm sorry. I _______ help you. I don't know how to do it.
- shouldn't
- must
- don't have to
- can
- shall
- needn't
- mustn't
- shouldn't
- would
- can't