Modal Auxiliary. Can and Could A modal auxiliary verb is used to modify the mood of a verb. Here is a list of the modal auxiliary verbs: Can: Can is used

Modal Auxiliary

Can and Could

• A modal auxiliary verb is used to modify the mood of a verb. Here is a list of the modal

• auxiliary verbs:• Can: “Can” is used to express ability,

willingness, permission, or possibility. The negative of can is “cannot” or the contraction “can’t”.

In this example “can” expresses the possibility.

• Example: I can cook dinner.• In this example “can” expresses the ability to cook

dinner.• Example: Can you pass me the ketchup?• In this example “Can” expresses the willingness pass

me the ketchup.• Example: Can I use your pencil?• In this example “Can” expresses the permission to use

your pencil.• Example: Intense light can hurt your eyes.

Directions: Say how “can” is used in each sentence. Circle “A” if it is used to express ability, “W” if it is used to express willingness, “Per” if it is used to express permission and “Pos” if it is used to express possibility.

• 1) I can tie my shoes. A W Per Pos• 2) Can I have a piece of gum? A W Per Pos• 3) If you ride a motorcycle, you can fall. A W

Per Pos• 4) Can you get me a drink of water? A W Per

Pos• 5) I can speak English well. A W Per Pos

Could

• “Could” has at least three functions. First, it can replace “can” and give the phrase a more conditional tone. Second, it can function as a the past tense of “can”.

• Third, it can function in the same way as “might” or “may”, suggesting that something is a possibility. The negative of can is “could not” or the contraction “couldn’t”.

“Could” functions the same way as “might” or “may” in this sentence.

• Example: You could have been an astronaut if you wanted to.

• In this example “could” expresses the conditional ability to be an astronaut in the past.

• Example: He couldn’t let me have his pencil because he needed it.

• In this example “couldn’t” expresses the lack of permission to have his pencil in the past.

• Example: Jane could be at the store right now.• In this example “could” expresses the possibility that Jane

is at the store in the present.

Directions: Circle the correct auxiliary modal verb in each sentence

• 1) I (could, can) help you with your homework now.

• 2) Five years ago, I (cannot, couldn’t) play the piano.

• 3) I (can, could) get an A on the test.• 4) I (can, could) run ten miles if I train hard

enough.• 5) We (can, could) speak English well.

May and Might

• A modal auxiliary verb is used to modify the mood of a verb. Here is a list of the modal auxiliary verbs:

• May: “May” is used to express permission or possibility. The negative of may is “may not”.

• Example: I may become a doctor.• In this example “may” is used to express the possibility

of me becoming a doctor in the future.• Example: May I have a glass of water?• In this example “may” is used to ask permission to

have a glass of water.

Might

• “Might” is used to express possibility. It differs from “may” in that the possibility it expresses is usually smaller. The negative of might is “might not”.

• Example: I might become a doctor when I grow up, but I doubt it.

• In this example “might” is used to express the small possibility that I will become a doctor when I grow up.

Directions: Circle the correct auxiliary modal verb in

each sentence.• 1) When I grow up, I (may, might) become an

engineer.• 2) There is a small chance the we (may, might) go to

the beach this weekend.• 3) There is a good change that we (might, may) have

to postpone the meeting.• 4) Billy and I (may, might) cook dinner tonight.• 5) The airplane (might, may) crash.• 6) You never know, I (may, might) become president

one day.

Must and Have to• A modal auxiliary verb is used to modify the mood of a verb.

Here is a list of the modal auxiliary verbs:• Must: “Must” has two functions. First it expresses a strong

belief. This belief is not based on fact, but rather on logic. Second, it expresses an obligation. The source of this obligation is internal (coming from oneself). The negative of must is “must not” or the contraction “mustn’t”.

• Example: My keys must be around here somewhere.• In this example “must” expresses a strong belief that is based

on logic.• Example: I must climb Mount Everest.• In this example “must” expresses the obligation to climb

Mount Everest that comes from an internal source (no one external to me is forcing me to do it).

Have to

• “Have to” has several functions. First it expresses a strong belief. This belief is not based on fact, but rather on logic. Second, it expresses an obligation. The source of this obligation is external (coming from your boss, the law, an authority). The negative of have is “do not have to”.

• Example: Yoko has to win this race to advance to the next round.

• In this example “has to” expresses a strong belief that is based on logic.

• Example: My mother says that I have to make my bed.• In this example “have to” expresses an obligation coming from

an external source (my mother).

Directions: Circle the correct auxiliary modal verb in each sentence.

• 1) My boss told me that I (have to, must) work overtime this week.

• 2) I (must, have to) get my hair cut before the dance.• 3) She (has to, must) pay monthly rent to live in her

apartment.• 4) Ted’s dad said that he (must, has to) clean his

room before he can play.• 5) I (have to, must) buy those pretty red shoes.

Ought to and Had better


• Ought to: “Ought to” is used to express the ideal (best) action. It is different from “should” in that it gives a sentence a more obligatory tone.

• The negative of ought is “ought not” or the contraction “oughtn’t”.

• Example: I ought to become a doctor because my father was a doctor.

• In this example “ought to” is used to express the ideal and somewhat obligatory action to become a doctor.

Had better

• “Had better” is used in the same way as “ought” (they are rough synonyms). The negative of had better is “had better not”.

• Example: He had better wash his hands before he eats.

• In this example “had better” is used to express the ideal and somewhat obligatory action to wash his hands before he eats.


• 1) I (had better / ought to, will) wash the dishes before mom gets home.

• 2) If she wants to, Hopi (had better / ought to, could) become a famous actor.

• 3) I can’t decide if I (had better / ought to, should) go to the movie tonight. I guess I

• will, because I don’t have anything else to do.• 4) Jerry (had better / ought to, might) mow the lawn before the

family picnic.• 5) The firemen (would, ought to / had better) extinguish the fire

quickly.

Shall and Should


• Shall: “Shall” is to express a future action. It is different than “will” in that it is used to express an order or prophecy. The negative of shall is “shall not” or the contraction “shan’t”.

• Example: I shall become a doctor.• In this example “shall” is used to express the prophecy of me

becoming a doctor in the future.• Example: Tomorrow, you shall climb to the top of Mt. Everest.• In this example “shall” is used to order or command a future

action.

Should

• : “Should” is used to express the ideal (best) action which happens in the past, present, or future. The negative of should is “should not” or the contraction

• “shouldn’t”.• Example: I think I should make chicken for dinner tonight.• In this example “should” is used to express that making

chicken is the best future action.• Example: I should get paid more for the hard work that I

do.• In this example “should” is used to express that it would be

ideal for me to get paid more for my present action.


• 1) Mom thinks you (should, shall) clean your room.

• 2) Trains (shall, should) go faster.• 3) This weekend (should, shall) be the best

weekend ever!• 4) I (should, shall) be a writer when I get older.• 5) Police (shan’t, shouldn’t) be allowed to drive

so fast.• 6) Our team (should, shall) have tried harder.

Will and Would


• Will: “Will” is used when you are volunteering to do something in the future, or when you are deciding at the time of speaking to do something in the future.

• The negative of will is “will not” or the contraction “won’t” (See “Using will and going” in the future tense folder of the advanced section of this website for more information on “will”).

• Example: I will cook dinner.• In this example “will” is used to volunteer to cook dinner in the future.• Example: I think I will go to the beach this Sunday.• In this example “will” is used to express a future action that is being

decided upon at the time of speaking.

Would• : “Would” has several functions. First, it functions as the past

tense of “will”.• Second, it functions as the conditional mood of “will”. Third, it is

used to be polite. The negative of would is “would not” or the contraction “wouldn’t”.

• Example: I would try to act like my father when I was young.• In this example “would” functions as the past tense of “will”.• Example: I would get a tan if I worked at the pool.• In this example “would” functions as the conditional mood of

“will”.• Example: I would like more tea please.• In this example “would” is used to be polite.


• 1) My dog and I (would, will) go for walks when she was younger.

• 2) I (will, would) buy new shoes if I had enough money.

• 3) I am feeling tired. I think I (would, will) go to sleep now.

• 4) I (will, would) like more milk when you get a chance.

• 5) I don’t think we (will, would) ever win the game.

Documents

Modal Auxiliary. Can and Could A modal auxiliary verb is used to modify the mood of a verb. Here is a list of the modal auxiliary verbs: Can: Can is used