Practical guide to English grammar
Modal verbs in English: list, uses, examples and exercises
Learn what are modal verbs in english, how to choose between can, could, may, might, must, should, will and would and how to construct affirmative, negative and interrogative sentences without translating word for word.
Don't memorize ten translations. Choose the intention first.
Essential concept
What are modal verbs in English and what are they for?
The modal verbs They are auxiliary verbs that modify the meaning of the main verb. They allow us to say not only what happens, but also whether an action is possible, necessary, advisable, permitted, probable or hypothetical.
In I work, you only claim that you work. In I can work, you express capacity; in I must work, obligation; and in I might work, possibility. The main verb does not change, but the intention does.
I should call · She can drive · They might arrive
- They do not add -s in third person: she can, no she cans.
- They do not use do/does/did to ask or deny.
- They come before the main verb and they change their nuance.
- They use infinitive without to, except ought to and semimodals.
- They are invariable: they retain the same shape with all subjects.
Map by intent
Uses of modal verbs: choose according to what you want to express
The same Spanish translation can correspond to several modals. To get it right, first decide whether you are talking about ability, permission, possibility, obligation, advice or deduction.
Capacity with modal verbs
It talks about what someone knows or can do now, could do before or will be able to do.
can · could · be able toI can speak English.I know how to speak English.
Permission with modal verbs
Request or grant authorization. The choice changes the degree of formality and courtesy.
can · could · mayMay I use your phone?Can I use your phone?
Possibility with modal verbs
Presents a situation as possible without stating that it will occur with certainty.
may · might · couldShe might arrive later.It may arrive later.
Obligation with modal verbs
It indicates a norm, a strong need or an external requirement.
must · have toYou must show your ID.You must show your ID.
Advice with modal verbs
It recommends an action without necessarily making it an obligation.
should · ought to · had betterYou should talk to her.You should talk to her.
Deduction with modal verbs
Express the degree of certainty you deduce from the available information.
must · might · can'tThey must be at home.They must be at home.
How to choose the correct modal verb in four steps
Ask what changes in the message: capacity, permission, probability, norm, recommendation or certainty? Don't start translating “power” or “duty.”
I want to ask permission → can, could or mayCheck if the situation occurs now, occurred in the past or refers to the future. Manners have limited forms and sometimes need an alternative.
Future capacity → will be able toMust, should and might do not transmit the same intensity. Decide whether to impose an obligation, give advice, or just admit a possibility.
must → obligación · should → consejoCan works in everyday situations; could creates polite distance; may is more formal. The relationship between speakers matters as much as grammar.
Could you help me? → petición cortésQuick inquiry
List of modal verbs in English and their meaning
This table brings together the main modal auxiliary verbs, their uses, their nuance and a translated example. Use it as a map; The context decides the final meaning.
| Modal verb | Main uses | Nuance | Example in English and Spanish |
|---|---|---|---|
| CanNegative: cannot / can't | capacity, informal permission and possibility | direct and everyday | I can help you today.I can help you today. |
| CouldNegative: could not / couldn't | past ability, possibility and polite request | more tentative than can | Could you open the window?Could you open the window? |
| MayNegative: may not | formal permission and possibility | formal or prudent | May I come in?Can I come in? |
| MightNegative: might not | uncertain or remote possibility | less secure than may | It might rain tonight.It may rain tonight. |
| MustNegative: must not / mustn't | strong obligation and logical deduction | maximum need or certainty | You must wear a seat belt.You must wear a belt. |
| ShouldNegative: should not / shouldn't | advice, recommendation and expectation | clear recommendation | You should get some rest.You should rest. |
| Ought toNegative: ought not to / oughtn't to | advice, moral duty and expectation | similar to should, somewhat more formal | We ought to be more careful.We should be more careful. |
| WillNegative: will not / won't | future, decision, promise and prediction | firm decision or expectation | I will call you tomorrow.I'll call you tomorrow. |
| WouldNegative: would not / wouldn't | polite request, preference, past habit and conditional | hypothetical or very polite | Would you like some coffee?Would you like a coffee? |
| ShallNegative: shall not / shan't | offer, suggestion and formal future | formal, frequent with I and we | Shall we start?Shall we start? |
Semimodal verbs and frequent alternatives
Individual guide
Modal verbs one by one: can, could, may, might, must, should, will and would
Learn the central function of each modal verb and enter its specific guide when you need all its nuances, negations and uses.
Candirect and everyday
It is used to express capacity, informal permission and possibility. Its negative form is cannot / can't.
I can help you today.I can help you today.
Couldmore tentative than can
It is used to express past ability, possibility and polite request. Its negative form is could not / couldn't.
Could you open the window?Could you open the window?
Mayformal or prudent
It is used to express formal permission and possibility. Its negative form is may not.
May I come in?Can I come in?
Mightless secure than may
It is used to express uncertain or remote possibility. Its negative form is might not.
It might rain tonight.It may rain tonight.
Mustmaximum need or certainty
It is used to express strong obligation and logical deduction. Its negative form is must not / mustn't.
You must wear a seat belt.You must wear a belt.
Shouldclear recommendation
It is used to express advice, recommendation and expectation. Its negative form is should not / shouldn't.
You should get some rest.You should rest.
Ought tosimilar to should, somewhat more formal
It is used to express advice, moral duty and expectation. Its negative form is ought not to / oughtn't to.
We ought to be more careful.We should be more careful.
Willfirm decision or expectation
It is used to express future, decision, promise and prediction. Its negative form is will not / won't.
I will call you tomorrow.I'll call you tomorrow.
Wouldhypothetical or very polite
It is used to express polite request, preference, past habit and conditional. Its negative form is would not / wouldn't.
Would you like some coffee?Would you like a coffee?
Shallformal, frequent with I and we
It is used to express offer, suggestion and formal future. Its negative form is shall not / shan't.
Shall we start?Shall we start?
Construction
Structure of the modal verbs: affirmative, negative and interrogative
Modal verbs already function as auxiliaries. That is why they do not need do, does or did and are placed directly before the subject in questions.
Affirmative sentence
Sujeto + modal + verbo baseShe can speak English.
She knows how to speak English.
Negative sentence
Sujeto + modal + not + verbo baseShe cannot come today.
She can't come today.
Interrogative sentence
Modal + sujeto + verbo base?Can she come today?
Can you come today?
Nuances that change the message
Differences between modal verbs that are often confused
Can expresses present capacity; could, past general ability or an option; be able to Allow other times.I can swim · I could swim at five · I will be able to swim again.
Can It is direct and informal; could sounds more polite; may It is formal to ask permission.Can I leave? · Could I leave? · May I leave?
All three questions may be correct; It changes the relationship and the tone.
All three express possibility. Might usually presents more uncertainty; could emphasizes a possible option.It may rain · It might rain · It could rain.
Must It usually reflects the speaker's demand or a strong rule. Have to It signals an external need and is best suited to the past or future.
I must call her.Speaker's decision.I have to wear a uniform.External rule.
Mustn't It means “it is prohibited.” Don't have to It means “not necessary.”
You mustn't park here.You can't park.You don't have to come.You can come, but it is not mandatory.
Should and ought to they advise. Had better adds urgency or a probable consequence.
You should rest.Council.You'd better leave now.There is a reason not to delay.
Will looks to the future or expresses will; would creates distance, politeness, past habit or a hypothesis.
Will you help me?Direct request.Would you help me?More polite.
look back
Modal verbs in past and perfect modals
To comment on a possibility, deduction, criticism or alternative about the past, we use modal + have + past participle. The structure does not change with the person.
She might have forgotten · You should have called
English in context
Examples of modal verbs in English and Spanish
These sentences with modal verbs cover ability, permission, possibility, obligation, advice, deduction, future, politeness and past. Notice that the main verb remains in base form.
Immediate correction
Common mistakes when using the modal verbs
The modal does not add -s in the third person.
After must the base verb is used without to.
The modal already acts as an auxiliary.
La negación se forma con modal + not.
Must no forma el pasado con -ed.
For a prohibition, use mustn't.
After the modal comes the base form.
Should no lleva to; ought to sí.
Check the nuance
Modal verbs exercises with answers
Complete each sentence with the modal verb that best fits. The correction explains the intention, so that you are not dependent on memorizing an isolated translation.
Frequently asked questions
Frequently asked questions about modal verbs in English
What are modal verbs in English?
They are auxiliary verbs that accompany a main verb to express capacity, permission, possibility, obligation, advice, intention or deduction. They don't just describe an action: they show the speaker's attitude toward that action.
What are the modal verbs in English?
The central modal verbs are can, could, may, might, must, shall, should, will and would. Ought to shares many of its characteristics. There are also semimodals such as have to, need to, be able to and had better.
What is the structure of the modal verbs?
In affirmative sentences, use subject + modal + base verb. In negatives, use subject + modal + not + base verb. In questions, use modal + subject + base verb. Ought to is an exception because it keeps to.
Do modal verbs take to?
Normally not: you say can go, must study and should call. Ought to yes it takes to. To express alternatives such as have to, need to or be able to to also appears because they are semi-modal constructions.
Are modal verbs conjugated?
They do not change with the person: I can, she can and they can. They do not add -s in the third person and do not use do, does or did to form questions and denials.
What is the difference between mustn't and don't have to?
Mustn't expresses prohibition: you must not do it. Don't have to expresses absence of obligation: it is not necessary, but you can do it if you want.
What is the difference between may, might and could?
All three can express possibility. May usually sounds neutral or somewhat formal; might presents the possibility as more uncertain; could indicates that something is a possible option depending on the circumstances.
How are modal verbs used in the past tense?
Could expresses general ability in the past. Past obligations normally use had to. For deductions, possibilities or criticism about the past, use modal + have + past participle: must have, might have, could have or should have.
How can I learn modal verbs faster?
Group them by intent, not by translation. Practice first ability, permission, possibility, obligation, advice and deduction; Then contrast two close modals within the same situation.