Grammar
Modal verbs for permission
At a shared office, one colleague says, Can I use this desk? Another asks, Could I borrow your charger? A notice on the wall says, Visitors may enter after 9:00. Each sentence deals with permission, but its setting affects the modal verb.
Choose a modal verb for permission by deciding whether you are making an everyday request, a careful request, a formal rule, or a prohibition.
Read and practice
Read the examples and try the written questions in this guide. Listening recordings are not available for this lesson yet.
Try the written questions
Could I use your phone for a minute? /kʊd aɪ juːz jɔː fə ə ˈmɪnɪt/
The short answer
Use can for ordinary permission, could for a more careful request, may in formal requests or rules, and must not or cannot when an action is forbidden.
Could I leave my suitcase here for an hour?
Why it works: Could makes this request sound careful. It does not refer to past time.
5 more examples
-
Can I open the window?
This is a normal, polite request in an everyday setting.
Not this:
May I openthe window? What changes: The request is still for permission, but may gives it a more formal tone. -
Could I speak to the manager for a moment?
Could makes a request sound more careful or less direct.
Not this:
Can I speakto the manager for a moment? What changes: Can is also possible, especially in ordinary conversation, but it is more direct. -
Guests may use the terrace until ten o'clock.
May gives permission in the style of a written rule or announcement.
Not this:Guests
can usethe terrace until ten o'clock. What changes: Can gives the same basic permission in a more conversational style. -
You must not take food into the laboratory.
Must not states a prohibition. The action is forbidden.
Not this:You
may not takefood into the laboratory. What changes: In a formal rule, may not can also mean that the action is forbidden. -
Passengers cannot cross the platform after the alarm sounds.
Cannot makes it clear that crossing is not allowed in this situation.
Not this:Passengers
may not crossthe platform after the alarm sounds. What changes: May not is suitable for a formal notice, while cannot is often clearer in speech.
Read the full guide
Start with the relationship and the setting. A quick request to a friend can use can. A request to a stranger, a customer, or a person in authority may need could or may. When you write a rule, choose words that show clearly whether an action is allowed or forbidden.
Choose the level of formality
Permission requests are not all the same. Think about who you are speaking to and how formal the situation is. Can I works well in many ordinary conversations. Could I sounds more careful. May I is formal and is common when you want to be especially polite.
Can I charge my phone here?
This is a direct everyday request. In a formal meeting, Could I charge my phone here? may fit the situation better.
Use can for everyday requests
Can is the usual choice when you ask a friend, colleague, shop assistant, or teacher for ordinary permission. It is polite when your voice and the rest of the request are polite. The next verb stays in the base form.
Can we leave our bags by the door?
We are asking whether leaving the bags is allowed. Say Can we leave, not Can we to leave.
Choose the modal for an everyday request: ___ I borrow your pen?
Use can: Can I borrow your pen?
Use could or may for careful requests
Could I is useful when you want to sound less direct. It can be a good choice with a customer, a supervisor, or a person you do not know well. May I has a formal tone. Both forms ask about present or future permission, even though could has the same form as the past of can.
Could we move to a quieter table?
Could softens the request. It does not mean that the request happened in the past.
May I ask one question before we begin?
May I is a formal way to ask for permission, often used in careful spoken situations.
Give permission in rules and notices
Written rules often use may to say what people are allowed to do. You may collect your ticket at the reception desk means that collecting it is permitted. Can is also possible when the message is less formal. Use the setting to choose the tone.
Members may reserve a study room for two hours.
This sounds like an official rule. The modal is followed by reserve, the base form of the verb.
Which word fits a formal notice: Visitors ___ take photographs in this room?
Use may: Visitors may take photographs in this room.
State a prohibition clearly
Use must not when a rule says that an action is forbidden. Cannot also makes a prohibition clear, especially when you speak to someone directly. In a formal notice, may not can have the same meaning. Do not confuse this use with may not for uncertain possibility.
You must not leave the gate unlocked.
This is a rule. It says that leaving the gate unlocked is forbidden.
Staff cannot share a guest's personal details.
Cannot tells the listener that sharing those details is not permitted.
Check the verb after the modal
Every modal in this lesson is followed by a base verb. Say can enter, could wait, may use, must not smoke, and cannot park. Do not add to or an ending such as -s after the modal.
You may leave after the presentation.
Leave is the base form after may. You may to leave and You may leaves are not standard forms.
Complete the rule: Guests must not ___ in the hallway.
Use the base verb: Guests must not smoke in the hallway.
Before you go
Remember this
Use can for everyday permission. Use could when you want a more careful request. Use may in formal requests and written rules. Use must not or cannot when a rule forbids an action. After each modal, use the base form of the verb.
Practice with the written examples
You can practice with the written questions in the Learn tab. Each answer includes an explanation.
Try the written questionsListening test not available yet
This lesson does not have the recordings needed for a listening test. Use the written questions in the guide to check your understanding.
Try the written questionsQuestions about "Modal verbs for permission"
Can I use can to ask for permission?
Yes. Can I is a common and polite way to ask for ordinary permission. It works well in many everyday situations, such as asking to open a window or borrow a pen. Use the base form of the next verb after can.
Can I open the window?
Why does could sound more polite than can?
Could often makes a permission request sound less direct and more careful. It does not make the request past. Choose it when the situation is formal, when you are speaking to someone you do not know well, or when you want a softer tone.
May I open the window?
When should I use may for permission?
Use may in formal requests and in written rules or announcements. May I asks for permission with a formal tone. A notice can use may to state what people are allowed to do. The verb after may stays in its base form.
Could I speak to the manager for a moment?
What does must not mean in a rule?
Must not means that an action is forbidden. It gives a clear prohibition, so use it for rules about actions that are not allowed. It is different from do not have to, which means that an action is optional rather than forbidden.
Can I speak to the manager for a moment?
Does may not always mean forbidden?
No. In a formal rule, may not usually means forbidden. In another context, it can express uncertainty, as in a sentence about something that perhaps will not happen. Look at the setting and the rest of the sentence before choosing the meaning.
Guests may use the terrace until ten o'clock.