I was teaching an English student how to use modal verbs correctly in conversation and I thought this would be a great blog post. Using my own experience as a native English speaker, and lots of extra research, I have found the best way to explain this grammar to ESL students.
The modal verb CAN shows that something is possible, allowed or somebody/something has the ability to do something. COULD is used as the past tense of can, or to talk about ability that was possible in the past. MAY and MIGHT are used to show that something is possible. MUST shows that something is necessary.
I have found that the best way to learn new grammar is to see it used in real examples. You’ll find many great example sentences in the body of this post. Examples that I use with my private students here in Japan that I have found to be very helpful.
Can Could May/Might Must
|CAN – We use the modal verb can to say that something is possible, allowed or somebody/something has the ability to do something.|
|COULD – 1) Could is sometimes used as the past tense of can.|
2) We use could to talk about ability or things that were possible.
3) We can use could to exaggerate our feelings for situations that are not real.
4) Could can also be used to say that something is possible now or in the future.
|MAY/MIGHT – May and might have the same meaning. They are used to show that something is possible.|
|MUST – 1) Must is used to say that something is necessary or very important (sometimes involving a rule or a law)|
2) We also use must to say that something is likely or logical
The definitions above are from www.oxfordlearnersdictionaries.com
Table of Contents
- How to use The Modal verb Can
- How to use The Modal verb Could
- How to use The Modal verbs May/Might
- How to use The Modal verb Must
- Bonus 1 Can Could May/Might Quiz
- Bonus 2 Downloadable Quiz PDF
- Bonus 3 Can Could May/Might Must Infographic
How to use the Modal verb CAN
The modal verb CAN is used with the infinitive form of a verb without TO.
Infinitive verb form: TO PLAY
Modal verb: CAN + infinitive form of a verb without TO.
Example: We CAN PLAY soccer in the field behind my house.
- “I can go to Disney tomorrow! My boss said I can take the day off.” [Go and take are both infinitives without TO.]
- “I can see Mt. Fuji from the 3rd-floor window on a clear day.”
- “Can you drive a motorcycle?” [In questions the subject can be placed in between CAN and the main verb.]
- “My new rice cooker can cook perfect rice in only 20 minutes. It’s amazing!”
- “Eric said he can meet us at the restaurant if he doesn’t work late.”
The negative form of can is cannot. We usually use the contraction can’t. [Can not becomes can’t]
- “Eric said he can’t meet us tonight because he has to work late.”
- I can’t drive a motorcycle.
One use of CAN is to have the ability to do something. We can sometimes say is able to instead of can but it is much less common.
- “My new rice cooker is able to cook perfect rice in only 20 minutes. It’s amazing!”
This grammar is fine but using can is more natural in conversation.
- “My new rice cooker can cook perfect rice in only 20 minutes.”
The modal verb can only has two tenses: present and past – can and could. This means there are times when we need to use (be) able to. For example:
- “Mike hasn’t been able to ski this winter because it hasn’t snowed very much.”
Hasn’t been is the Perfect Tense. You will find a detailed study of Perfect Tense English grammar HERE.
Also when talking about the future.
- I will be able to drive a motorcycle after I finish a driving course.
*This sentence is describing something that will be possible in the future.
How to use the Modal verb COULD
There are a few different ways that we use the modal verb could in English conversation.
1) Could is sometimes used as the past tense of can.
- “From the 3rd-floor window of the high school I used to teach at you could see Mt. Fuji on a clear day.” – In the past this was possible, but I don’t teach there anymore.
- “When I was 10 my family lived very close to my school. I could walk there in just 5 minutes.” – In the past this was possible, but I don’t live there anymore.
The modal verb could can also be used to talk about someone or something that had the ability to do something or was allowed to do something.
- “When I was in high school, I could run a kilometer in 3.5 minutes.” – I had this ability in the past.
- “They say that famous magician Harry Houdini could hold his breath for over 3 minutes.” – this was an ability that Harry Houdini had when he was alive. (link)
- “My old rice cooker could also make cakes, bread. cook oatmeal, and more. It was really awesome.” – The rice cooker that I owned in the past had many abilities.
- “At my family’s old cottage, there were no other homes within 5 kilometers. We could play music as loud as we wanted.” – We had permission to play loud music at my family cottage because there was no one close to us.
[No None and Non – Learn the difference (50 examples + PDF)]
The negative form of could is could not. This is often spoken as the contraction couldn’t.
- “If it was cloudy you couldn’t see Mt. Fuji.”
The modal verb Could – Common mistake
General possibility VS Specific possibility
A general possibility with could:
- “We could play music as loud as we wanted.” This was generally true any time we went to the cottage.
When we talk about one specific past situation the grammar was able to is a better choice.
- “We all thought Diane would be late, but she was able to make it on time.” – This sentence is talking about one specific situation.
- “Yesterday I was finally able to beat my brother at chess. It was the first time in 8 years.” – This was the first time in 8 years that I beat my brother in chess. This is a specific time.
*The negative contraction couldn’t (could not) is okay for both general and specific sentences.
- “We couldn’t see Mt. Fuji if it was cloudy.”
- “I beat my brother at chess yesterday so I was feeling confident. I challenged my Dad but I couldn’t beat him. He is a great chess player.”
My Dad can beat anyone in our family at chess. He’s the house chess champion.
2) Could is also used to talk about actions that are possible now. We often use it to suggest possible future actions.
- A: “What would you like to do tonight?”
B: “We could go and see a movie.”
A: “That sounds great. We could have dinner before the movie at the new restaurant beside the theater. I heard it’s really good.”
Learn how to Make Suggestions in English Conversation (Real examples) at my blog post.
3) We can use could for situations that are not real. This is used to exaggerate a feeling or an idea.
Here is a common English expression:
- ”I’m so hungry I could eat a horse.” – I couldn’t really eat a whole horse, but this expression shows that I am VERY hungry.
- “I am so angry right now I could scream!” – I’m not going to scream, I just want to emphasize that I am very angry.
- “I love this ice cream. I could eat 50 bowls right now.” – I couldn’t really eat 50 bowls of this ice cream, but I want to show how much I love it.
We wouldn’t say –
- “I love this ice cream.
I can eat 50 bowls right now.”
I could eat ice cream all day every day.
4) Could can also be used to say that something is possible now or in the future. (This is also how we use May and Might)
- “You’d better bring your umbrella. It could rain tonight.” = It’s possible that it will rain tonight.
- “Mike said the boss will be out today, but he could be lying.” = It’s possible that Mike is lying.
5) Could can be used to make a polite request.
- Could you help me wash the dishes?
- Could you let me know when Janice arrives? I need to speak with her.
- Could I borrow your phone for a minute?
“Could I borrow your iPhone? I want to look up the address of the restaurant.”
Using could in the past tense
We use could with the perfect tense (could have + past participle) to talk about the past.
- “We could have seen Mt. Fuji if it wasn’t so cloudy yesterday.” (Seen is the past participle of the verb to see.)
- “Things were bad, but they could’ve been worse.” (Been is the past participle of the verb to be.) This example means that even though things were bad it was possible for them to have been worse. In a small way, we were lucky.
- “Did you walk home in the rain? If you called me, I could have given you a ride.” (Given is the past participle of the verb to give.) This example means it was possible for me to give you a ride.
How to use the Modal verbs MAY/MIGHT
May and might have the same meaning. They are used to show that something is possible.
- It may rain tonight.
- It might rain tonight.
The grammar pattern for these modal verbs looks like this:
|be + adjective – true, late, free|
|(Subject)||may/might||be + verb ~ing – working, coming, studying|
|verb – move, like, want|
- That story might be true, but it’s hard to believe.
- Scott may be late.
- I might be working on Saturday.
- It will be a fun party. I heard that Kevin might be coming.
- Helen got a promotion. She might move to a bigger office now.
- Helen may want to stay in her current office. She likes it.
To make the negative form we just need to add not after may/might.
- That story might not be true.
- I heard that Kevin might not be coming to the party. That’s too bad, I like Kevin.
- Even though Helen got a promotion she might not move to a bigger office. She likes her current office. It has a big window.
My current office is also close to the coffee machine. I may not move to another office.
What’s the Difference between May Be and Might Be?
May be and Might be mean the same thing. They are both showing possibility.
In both cases, the verb be will be followed by an adjective or a verb in its gerund form. (+ -ING)
The adverb maybe comes from the phrase “It may be (that)”
- Maybe we should wait.
- I asked my Dad if I could borrow the car on Saturday night. He said “Maybe.”
- I go to the coffee shop maybe once or twice a week.
Maybe I should drink coffee at home. I can save money.
Using May/Might in the past tense
To use the modal verbs MAY and MIGHT in the past tense we use the same grammar as COULD. (have + past participle)
|been + adjective / at a place|
|(Subject)||may/might||have||been + verb ~ing|
Scott may have gone to baseball practice early.
*Been is the past participle of TO BE
- I called Ian but he didn’t answer. He may have been asleep. (Been + the adjective asleep)
- Laurie didn’t play well at today’s game. She might have been tired. (Been + the adjective tired)
- We didn’t see Scott on the bus this morning. He might have been at baseball practice. (Been + at a place)
- Peter didn’t reply yet. He might have been eating dinner when I texted. (Been + eating)
- A: The field is wet. Did it rain?
B: I don’t think so. They may have been using the sprinkler. (Been + using)
- Dillon can’t find his sunglasses. He might have left them at the office. (Left is the past participle of TO LEAVE)
- Grace is late. She may not have heard that we moved up the meeting start time. (Heard is the past participle of TO HEAR)
May / Might FUTURE TENSE
When May/Might describe a future possibility we will use them with be + verb ~ing form.
- My family might be going to California for summer vacation.
- William is trying to get seats for tomorrow night’s concert. We might be watching the show live!
The verb TO BE + verb ~ing is how we describe a future action that has already been decided. When we use this grammar with a modal verb it shows a possibility that we are considering. Visit my FUTURE TENSE grammar post for a deeper study and more examples of how to use the future tense.
The modal verbs Could, May, Might – Common mistake
*Could, May, and Might can have the same meaning but the negative Could not and May not/Might not do not mean the same thing.
Couldn’t means something is not possible.
- A: Did your brother like his birthday present?
- B: I don’t know. He couldn’t have received it yet, I just mailed it yesterday. (Received is the past participle of TO RECEIVE)
*It’s not possible that he has his gift yet.
May/Might not means it’s possible, but I’m not sure.
- A: Did your brother get his birthday present yet?
B: I don’t know. I sent it 3 weeks ago but he might not have got it yet. I haven’t talked to him recently. (Got is the past participle of TO GET)
*Maybe he has his gift already and maybe he doesn’t. Both are possible.
(In North American English, the past participle of get is gotten – he might not have gotten it yet.)
My brother might not have got his gift yet.
How to use the Modal verb Must
The modal verb must has two basic uses.
- used to say that something is necessary or very important (sometimes involving a rule or a law)
- You must put your garbage on the curb by 7 a.m.
- All visitors must park behind the building.
- Lights must be turned off by 10 p.m.
- used to say that something is likely or logical
- Jason must have gone out. He’s not answering his phone now.
- You can study non-stop for 4 hours. You must be hungry.
- This car only costs $4,000? You must be kidding!
That price is too low. There must be something wrong with the car.
Must = have to/has to
Must and Have to/Has to can have the same meaning.
- You have to put your garbage on the curb by 7 a.m.
- Jason has to be home by now.
Have got to/Has got to is also possible
- All dorm room lights have got to be turned off by 10 p.m.
May/might Vs. Must
May/might show that something is possible whereas Must shows that something is necessary.
- “Jim may/might be able to come with us to Disney tomorrow, but he’s not sure yet.”
It is possible that Jim can come with us tomorrow.
- “You must be able to cook Italian food if you want to work at this restaurant.”
If you can’t cook Italian food you can’t work at this restaurant.
Watch the video below. Improve your English listening skills while you review this important English grammar.
Can Could May/Might Quiz
Printable Modal Verb Quiz
Download the Quiz as a printable PDF worksheet. Great for teachers to use with private or group classes. ↓
Do you want to sound like a native speaker? Use more IDIOMS! This awesome post is a great place to start – Idiom$ About MONEY (120 Common English Financial Idioms)
Can Could May/Might Must Infographic
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