When you ask someone, “Can I go out?” you might get a sarcastic “You can, but you may not.” response. That’s because “can” and “may” are modal verbs that suggest different meanings. My dad used to drive me crazy as a kid with remarks like that.
Modal verbs are a type of verb found before the main verb. Keep reading to learn modal verbs’ definitions and uses. You’ll also see how to correctly use them in sentences because I’ve got a ton of examples to share with you.
What is a Modal Verb?
Modal verbs are verbs that express advice, capability, proposals, or hypothetical conditions. These verbs are different from normal verbs, such as tell, think, and reuse.
This type of verb can be found before an action verb to give it an additional meaning. As auxiliary verbs, modal verbs cannot stand independently to complete a sentence.
Here’s an example of how a modal verb gives shades of meaning to a sentence.
- Trina and Joan play the piano.
Trina and Joan might play the piano.
Another verb always follows modal verbs in base form. Remember not to conjugate the verb. For example:
- Incorrect: She can plays the piano.
Correct: She can play the piano.
What are the 9 Modal Verbs?
The nine modal verbs with modal meanings are:
- Shall.
- Should.
- Can.
- Could.
- Would.
- Will.
- May.
- Must.
- Might.
Other modal verbs you can use are ought to, need to, have to, and might as well. We can use these modals to express obligation, permission, and suggestion,
What are the 4 Main Types of Modals?
Modal verbs can be divided into four main types.
Modals of Deduction
Modals of deduction are also known as modals of probability or certainty. These verbs help the speaker show that they are confident or not of something. The primary modals of deduction are must, might, may, and could. For example:
- The students must be practicing right now.
- I may not be here for a long time.
Modals of Ability
Modals of ability show one’s ability or lack thereof. The main ability modal verbs are can, cannot, be able to, and could. For example:
- She’s been able to drive a truck since she was sixteen.
- He cannot understand English.
Modals of Requests, Offers, and Permission
Modal verbs of requests, offers, and permission help the speaker inquire about permission. The modals in this category are can, could, and may. For example:
- May I go to the bathroom?
Modals of Advice, Obligation, and Prohibition
This type of modal verb helps say something important or not. You can also use them to make suggestions and give advice. These modals include have to, must, can, and cannot. For example:
- You must do all your homework before you go out.
- I think we can park in this spot.
What’s the Difference Between Modal and Auxiliary Verbs?
A helper verb or auxiliary verb is a type of verb that adds grammatical meaning to clauses’ meanings. You can use these verbs to show modality, tense, voice, and more. That means modal verbs are only a type of auxiliary verbs. For example:
- I should go back to sleep.
In this sentence, should adds grammatical functions to the sentence by showing obligation. Other modal verbs can be used to show willingness, certainty, necessity, ability, permission, advice, and possibility.
How Do We Use Modals?
There are many ways we can use modal verbs. Follow these formulas when constructing your sentences.
Can, Could, Be Able To
Use these modal verbs to show a subject’s ability or lack of ability. Remember to add not for the negative form.
To show the present and future tense, follow these structures.
- Can/can’t + base form
I can’t go to the mall later. (future)
Gina can sing well. (present)
- Am/is/are/will be + able to + base form.
She is able to speak Italian. (present)
My friends will be able to attend the seminar. (future)
- Am not/isn’t/won’t be + able to + base form.
Freddie won’t be able to buy the new toy. (future)
The past form of modal verbs showing ability follows this verb structure. Note that you can also use could for an action happening over a period of time.
- Could/Couldn’t + base form of verbs
I could fly kites when I was a kid. (positive form)
I couldn’t reach the ceiling when I was young. (negative form)
The modal verb can can also be used to express permission or request permission. Here are the most common structures.
- Can + subject + base form (Note that this structure is used to request for permission in informal situations. Do not use this in formal situations).
Can you buy me the new album?
- Can/Can’t + base form
You can borrow my car.
Follow this structure when making a polite suggestion.
- Could + base form
You could change your hairstyle.
The family could visit the castle tomorrow.
Modal verbs can also express the possibility and impossibility of something using this construction.
- Can/Can’t/Could/Couldn’t + base form
You can arrive at the venue early if you leave now.
May, Might
Like can and could, may and might can show the possibility or negative impossibility of something.
- may/might + base form
It might be sunny tomorrow.
Mike might attend the party tomorrow night.
- May not/might nor + base form
The Rooneys may not go to Canada this Christmas.
Follow this verb combination to make a polite suggestion.
- May + subject + verb’s base form.
May I excuse myself?
The modal verb may is useful when giving formal permission or prohibition.
- May/may not + base form
You may open your notes while answering the test.
Use may as well or might as well to create a suggestion for the last resort.
- May/might as well + base form
The class may as well skip the examination.
Must, Have to, Need to, Needn’t, Don’t Have To
These modal verbs usually show necessity or requirement. Have to shows external obligation because the obligation comes from outside the speaker. The same is true with must and need to. Here are some ways to use them.
- must/need to/have to/ + base form (for present and future tenses).
One must wear comfortable shoes for a successful hike.
They need to download the application to answer the test.
You have to light a candle for her tonight.
- Had to/needed to + base form of the verb (past tense).
She needed a break from her student government duties.
I had to go to the gym last weekend.
Notice how must cannot be expressed in past tense sentences.
When trying to show that you are almost sure about something, follow this modal and main verb combination.
- Must + base form of the verb.
Your parents are singers, so your voice must be excellent.
Use this formula when persuading someone.
- Must/have to + base form
You must buy this bag. It’s spacious and perfect for school.
You have to listen to their music now.
Follow this structure when prohibiting someone.
- Must not + base form
You must not drink and drive.
Shall, Should, Ought To
The modal verb shall is ideal for giving assistance or respectful suggestions. You can use it when you are certain of a positive answer
- Shall + subject + verb’s base form
Shall we dance?
If you’re not sure of a positive answer, the correct verb to use should. Below is the proper construction.
- Should + subject + root verb
Should I ask my mother about it?
Use shall in formal or legal situations. These sentences usually have a passive voice.
- Shall + be + past participle.
The plaintiff shall be permitted to talk.
Should is ideal for making predictions or showing expectations about something. These sentences are also in passive voice.
- should/shouldn’t + base form
This book should be finished next week.
You shouldn’t be worried. Turbulence isn’t dangerous.
Use should when giving advice. Here’s the correct structure with some common examples.
- Should + base form
The manager should attend meetings on time.
You should submit your paper on time.
Ought to shows a sense of obligation like should.
- Ought to + base form
Katy ought to have her teeth checked this week.
Will and Would
Will is a modal verb used to show the simple future tense.
- Will/won’t + base form
I will pick you up later.
You can even use will and would to request something.
- Will/Would + you + base form
Will you open the door for me?
Would you care if I borrowed your phone?
Would is a modal verb that expresses habitual past action.
- Would/Would not + base form of the verb
When I was seven, we would always eat breakfast at his restaurant.
Using Modal Verbs in Sentences
You can use modals in the future and present time, showing different verb tenses to express hypotheticals and general events. But remember that not all modals can refer to a past situation.
Present Tenses
Here’s how to express verb phrases with modals in different present tenses.
Simple Present Tense
The simple present tense is the easiest. Just place the modal verb before the main verb, then use the base form of the verb. For example:
- I can eat that entire tub of ice cream.
When asking a question in the simple present tense, write the modal verb, subject, then the root verb. For example:
- Can I eat an entire tub of ice cream?
Present Continuous
The present continuous tense shows action in progress or habitual action. Write the modal verb, be, and the -ing form of the verb. For example:
- I should be eating an entire tub of ice cream.
Present Perfect Continuous
This verb tense helps you express something that started happening in the past and continues in the present. But its grammatical function changes because there’s a modal verb before it.
The present perfect continuous tense requires a modal verb, “have been,” and the -ing verb form. For example:
- I should have been eating ice cream.
In this sentence, should have been expresses what one thinks should have occurred in the past but did not occur.
Past Tenses and Present Perfect
Not all modal verbs can be expressed in the past tense, especially when you want to describe a hypothetical situation. The general rule is that can and will have simple past forms.
Simple Past
Conjugate can and will into their past forms: could and would. Have to become had to, while need to becomes needed to. But other modal verbs should not be used in past tense sentences. As usual, the formula is the modal verb plus the root verb. For example:
- In eighth grade, I could not submit my English project on time.
- I was at the department store because I needed to buy art materials.
Past Continuous
The past continuous or past progressive tense expresses an ongoing action happening at a certain point in the past. As with simple past, past continuous only uses could and would. After the modal verb, write have and the past participle of the verb. For example:
- I could be enjoying the sunset in Santorini right now.
In this sentence, could be is used to express something untrue or hypothetical.
Present Perfect
The present perfect tense is another verb tense that uses past actions related to the present. It can also show an action continuing into the present. Use have and the past participle instead of the bare infinitive of the main verb.
Use the modal verb have even if the subject is third-person. For example:
- I must have forgotten the time.
In this sentence, must have does not express something essential. Instead, must have is used when we feel sure about what happened.
If you are using the modal verb can, transform it into the past tense, could. For example:
- I could have gotten into Brown if I did more extra-curricular activities.
In this sentence, could have means something you had the ability to perform in the past but failed or didn’t do.
Future Tense
The simple future tense is relatively easy to use with modals. That’s because most of them already use will. You can also use should, shall, and can as alternatives. All you need to do is use the modal verb and then the base form of the verb. For example:
- We can eat ice cream tomorrow.
Other Rules for Using Modals
Modals are more straightforward than you think. Remember these four rules when using modal verbs.
Constructing Verb Phrases
As seen in the structures above, modal verbs always come first in verb phrases. Then, they are followed by bare infinitives. For example:
- Would/Would not + base form of the verb
A few years ago, my family and I would go to the park every weekend.
- Must + base form of the verb.
Lina spent three years in Paris and two years in Florence. She must be good at French and Italian.
Remember that the bare infinitive does not include the word to. For example:
- Incorrect: Nora might to be with us this weekend.
Correct: Nora might be with us this weekend.
Do not use to be as the full infinitive after the words might, should, will, may, or can. The correct term to use is be. That means you can also say, “Nora will be with us this weekend,” “Nora should be with us this weekend,” or “Nora can be with us this weekend.”
Don’t Add -s, -ed, or -ing to Modals
Try to think of modal verbs as the linking verb is. Don’t change them into the present, future, or past form. Modal verbs do not require these suffixes to show a verb tense. For example:
- Incorrect: I canned climb trees when I was young.
Correct: I could climb trees when I was young.
Negative and Interrogative Forms
Like other auxiliaries, modal verbs can be expressed in interrogative and negative forms. I would add the word not after the modal verb for negative sentences. For example:
- You must not go inside.
For interrogative sentences, the formula is modal verb + subject + base form.
- Will she go with us?
Modal Verbs in a Nutshell
The English language is composed of several types of verbs, like Irregular verbs, regular verbs, copular verbs, dynamic verbs, and modal verbs. And you’ve probably seen modal verbs hundreds of times without knowing what they are.
Remember that modal verbs express advice, abilities, possibility, permission, or special conditions. When writing verb phrases, put the modal verbs first, then the bare infinitive.