Modal auxiliary Verbs:
There are 9 core modal auxiliary verbs (helping verbs): can, could, may, might, must, shall, should, will, and would (ought is also used but not as common)
Each of these modal auxiliary verbs have a function in a sentence
List of Modal Verbs
Must – to have to, or to be highly likely. Must can be used to express 100% certainty, a logical deduction or prohibition depending on the context.
Can – to be able to, to be allowed to, or possible. Can is a very common modal verb in English. It’s used to express ability, permission and possibility.
Could –to be able to, to be allowed to, or possible. Could is used when talking about an ability in the past or for a more polite way to ask permission.
May – to be allowed to, it is possible or probable
Might – to be allowed to, possible or probable. Might is used when discussing something that has a slight possibility of happening, or to ask for permission in a more polite way.
Need – necessary
Should – to ask what is the correct thing to do, to suggest an action or to be probable. Should usually implies advice, a logical deduction or a so-so obligation.
Will – to suggest an action or to be able to
Would – to suggest an action, advice or show possibility in some circumstances
Each of these modal auxiliary verbs have a function in a sentence
List of Modal Verbs
Must – to have to, or to be highly likely. Must can be used to express 100% certainty, a logical deduction or prohibition depending on the context.
- It must be hard to work 60-hours a week. (probable)
- You must listen to the professor during the lecture. (necessity)
- She must not be late for her appointment. (necessity)
- It must not be very hard to do. (probable)
Can – to be able to, to be allowed to, or possible. Can is a very common modal verb in English. It’s used to express ability, permission and possibility.
- It can be done. (possible)
- She can sleepover at Sara’s house this weekend. (allowed to)
- The car can drive cross country. (able to)
- It cannot be done. (impossible)
- The doctor said he cannot go to work on Monday. (not allowed to)
- She cannot focus with the car alarm going off outside. (not able to)
Could –to be able to, to be allowed to, or possible. Could is used when talking about an ability in the past or for a more polite way to ask permission.
- Mark could show up to work today. (possible)
- Could I come with you? (allowed to)
- When I was in college I could stay up all night without consequence. (able to)
- Mark could not come to work today. (possible/allowed)
- Last night I could not keep my eyes open. (able to)
May – to be allowed to, it is possible or probable
- May I sit down here? (allowed to)
- I may have to cancel my plans for Saturday night. (possible/probable)
- She may not arrive on time due to traffic. (possible)
Might – to be allowed to, possible or probable. Might is used when discussing something that has a slight possibility of happening, or to ask for permission in a more polite way.
- Chris might show up to the concert tonight. (possible/probable)
- Might I borrow your computer? (Many people don’t say this in American English, instead they would say Can I borrow your computer? Or May I borrow your computer?)
Need – necessary
- Need I say more? (necessary)
- You need not visit him today. (not necessary)
Should – to ask what is the correct thing to do, to suggest an action or to be probable. Should usually implies advice, a logical deduction or a so-so obligation.
- Should I come with her to the dentist? (permission)
- Joe should know better. (advice/ability)
- It should be a very quick drive to the beach today. (possibility)
- Margaret should not jump to conclusions. (advice)
Will – to suggest an action or to be able to
- John will go to his second period class tomorrow. (action)
- It will happen. (action)
- She will see the difference. (be able to)
- Eva will not drive the Volkswagen. (not do an action)
- Joe will not study tonight because he has to work. (not be able to)
Would – to suggest an action, advice or show possibility in some circumstances
- That would be nice. (advise/possibility/action)
- She would go to the show, but she has too much homework. (action)
- Mike would like to know what you think about his presentation. (action)