Modal Verbs: Permission Practice Tests with B1 Grammar Rules & Examples

Modal Verbs for Permission

When we want to ask for permission to do something, or when we give or refuse permission to someone else, we use special verbs called modal verbs. A modal verb is a helper verb that goes before the main verb to add extra meaning.

In this lesson, we focus on modal verbs for permission. These are the words we use to say "Is it okay if I...?" or "Yes, you can..." or "No, you must not..."

The main modal verbs for permission in English are:

• can
• could
• may
• might
• must not / mustn't

Let's look at a simple situation before we learn the rules.

Marco is a student. He is in the classroom. He wants to open the window. He asks his teacher:

"Can I open the window, please?"

His teacher says: "Yes, you may open the window."

In this example, Marco uses can to ask for permission. His teacher uses may to give permission. Both of these are modal verbs for permission.

Rule Breakdown: How to Use Modal Verbs for Permission

Modal verbs follow one simple rule. They always come before the base form of the main verb. The base form is the verb with no -s, -ed, or -ing ending.

Pattern:
Subject + modal verb + base verb + (rest of sentence)

Examples:
I can leave early today.
She may use my phone.
You must not enter this room.

Notice that the modal verb does not change for he, she, or it. We do not add an -s.

❌ She cans go.
✅ She can go.

Can – Asking for and Giving Permission

Can is the most common and most informal modal verb for permission. We use it in everyday conversations with friends, family, and people we know well.

Asking for permission with "can":

Can I + base verb + ...?

Examples:
Can I sit here?
Can I borrow your pen?
Can I go to the bathroom, please?

Giving permission with "can":

Yes, you can + base verb.

Examples:
Yes, you can sit here.
Yes, you can borrow my pen.

Refusing permission with "can't / cannot":

No, you can't + base verb.

Examples:
No, you can't sit here. This seat is taken.
No, you cannot park here.

Note: cannot is the full form. can't is the short form (contraction). Both mean the same thing.

Could – Asking for Permission Politely

Could is more polite than can. We use it when we want to sound respectful — for example, when speaking to a teacher, a manager, a stranger, or an older person.

Asking for permission with "could":

Could I + base verb + ...?

Examples:
Could I leave the meeting early?
Could I use your computer for a moment?
Could I ask you a question?

Important: We use could to ask for permission, but we do not usually use it to give or refuse permission. We reply with can / can't or may / may not.

Example:
"Could I open the door?"
"Yes, you can open the door." ✅
"Yes, you could open the door." ❌ (This sounds strange.)

May – Formal Permission

May is the most formal modal verb for permission. We use it in formal situations — in official rules, notices, polite business conversations, or when speaking to someone important.

Asking for permission with "may":

May I + base verb + ...?

Examples:
May I come in?
May I speak to the manager, please?
May I take a seat?

Giving permission with "may":

Yes, you may + base verb.

Examples:
Yes, you may come in.
You may take a seat.

Refusing permission with "may not":

No, you may not + base verb.

Examples:
You may not enter without a ticket.
Students may not use mobile phones during the exam.

Note: may not does not have a common contraction in formal English. We do not say mayn't in modern English.

Might – Tentative or Uncertain Permission

Might is sometimes used to ask for permission, but it is very formal and quite rare in modern spoken English. It sounds even more polite and hesitant than could.

Asking for permission with "might":

Might I + base verb + ...?

Examples:
Might I suggest a different approach?
Might I borrow this for a moment?

You will mostly see might for permission in written or very formal spoken English. In everyday speech, can, could, or may are much more common.

Must Not / Mustn't – Refusing or Forbidding Permission

We use must not (or mustn't) to say that something is not allowed — it is forbidden. This is stronger than can't or may not.

Examples:
You must not smoke in this building.
Students mustn't copy each other's work.
You must not touch the exhibits.

We often see must not on signs, notices, and in official rules.

Summary Table: Modal Verbs for Permission

Modal Verb	Use	Formality	Example
can	Ask / Give / Refuse permission	Informal / Everyday	Can I sit here? Yes, you can.
can't / cannot	Refuse permission	Informal / Everyday	You can't park here.
could	Ask for permission politely	Polite / Neutral	Could I use your phone?
may	Ask / Give / Refuse permission	Formal	May I come in? Yes, you may.
may not	Refuse permission (formal)	Formal	You may not enter this area.
might	Ask for permission (very formal / rare)	Very formal	Might I make a suggestion?
must not / mustn't	Forbid permission strongly	Formal / Official	You must not touch the exhibits.

Formality Scale: Which Modal Verb to Choose?

Choosing the right modal verb depends on the situation. Here is a simple guide from most informal to most formal:

Situation	Best Choice	Example
Talking to a friend	can	Can I try your food?
Talking to a teacher or colleague	could	Could I hand this in tomorrow?
Talking to a manager or stranger	could / may	Could I / May I speak with you?
Official signs and notices	may not / must not	Visitors may not use this entrance.
Very formal written English	might / may	Might I enquire about the position?

Negative Forms and Contractions

Here are the full forms and contractions for modal verbs for permission:

Full Form	Contraction	Example
cannot	can't	You can't leave yet.
could not	couldn't	(Not commonly used for permission)
may not	(no contraction used)	You may not enter.
must not	mustn't	You mustn't run in the corridor.

Remember: cannot is written as one word, not two. Can not (two words) is possible but much less common.

Question Forms with Modal Verbs for Permission

To ask for permission, we put the modal verb before the subject (usually I or we).

Pattern for questions:
Modal verb + I / we + base verb + ...?

Question	Positive Answer	Negative Answer
Can I open the window?	Yes, you can.	No, you can't.
Could I leave early?	Yes, of course you can.	No, I'm afraid you can't.
May I use the phone?	Yes, you may.	No, you may not.
Can we bring food in here?	Yes, you can.	No, you can't bring food in here.

Important Differences and Special Cases

Can vs. Could: Not About Past and Present

When we use could for permission, it does not mean past tense. Both can and could are used in the present to ask for permission. The difference is only about politeness.

Can I leave? → informal, direct
Could I leave? → polite, more respectful

May Not vs. Might Not: Different Meanings

Be careful! may not and might not do not always mean the same thing.

• You may not enter. → Permission is refused. (You are not allowed to enter.)
• She might not come. → This is about possibility, not permission. (Perhaps she will not come.)

Permission vs. Ability: "Can" Has Two Meanings

Can is also used to talk about ability — what someone is able to do. This is different from permission.

Can I sit here? → Asking for permission (Am I allowed to sit here?)
I can swim. → Talking about ability (I know how to swim.)

The context makes the meaning clear.

Giving Permission to a Third Person

When we give permission to someone else (not "you"), we can say:

He can leave early today. (I allow him to leave.)
She may use the computer. (She has permission to use it.)

Common Mistakes

❌ Can she goes now?
✅ Can she go now? (Always use the base form of the verb after a modal.)

❌ Could I to use your pen?
✅ Could I use your pen? (Do not use "to" after a modal verb.)

❌ She cans leave early.
✅ She can leave early. (Never add -s to a modal verb.)

❌ May I to come in?
✅ May I come in? (No "to" after modal verbs.)

❌ You cannot to park here.
✅ You cannot park here. (No "to" after cannot.)

❌ Could you leave? Yes, I could. (giving permission)
✅ Could you leave? Yes, you can. (Use can or may to give permission, not could.)

❌ Can not (two words for ability/permission)
✅ Cannot (one word) or can't (contraction).

Modal Verbs for Permission: Quick Summary

Here is what we have learnt about modal verbs for permission:

• We use modal verbs to ask for, give, and refuse permission.
• The main modal verbs for permission are: can, could, may, might, must not.
• Modal verbs are always followed by the base form of the verb (no -s, -ed, or -ing).
• Modal verbs do not change for he, she, or it.
• Do not use "to" after a modal verb.
• Can is informal and everyday. Could is polite. May is formal. Might is very formal and rare.
• Must not / mustn't is used to strongly forbid something.
• Use can or may to give permission in a reply — not could.

Now practise modal verbs for permission in the exercises below.