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Modal verbs

Level: beginner

The modal verbs are: 



We use modals to show if we believe something is certain, possible or impossible:

My keys must be in the car.
It might rain tomorrow.
That can't be Peter's coat. It's too small.

We also use them to do things like talk about ability, ask permission, and make requests and offers:

I can't swim.
May I ask a question?
Could I have some tea, please?
Would you like some help?

Modal verbs




Hello! I'd like to seek explanation on the following examples from a book. These pertain to school rules:


Students MAY bring drinks to school, but we CAN'T drink them during classes.

Students CAN'T come to school by motorcycle.

We MUSTN'T use mobile phones during classes.

We CAN work part-time.

We CAN'T get a driver's license.

We CAN have lunch at the school yard.


Students MUST wear their uniform correctly everyday at school.

We MUST wear our indoor shoes.


For the (A) sentences: Is MAY interchangeable with CAN, vice versa? Are CAN'T, MAY NOT, and MUSTN'T also interchangeable? If they are, how can we know which modal verb to use, especially in sentences like these? Does it matter if we use one instead of the other? What implications do they have?

For (B): What should be our basis for using whether "MUST" or "HAVE TO"?

Hoping to hear your feedback.

Thank you so much in advance!

Hello Timmy Ferrer,

I believe that all of your questions about the (A) sentences are answered on the Permission and Suggestions and obligations pages in this section. Please have a look there and if anything is still not clear after that, you are welcome to ask us again.

'you have to do something' means it is necessary to do it or that you are obliged to do it. 'you must do something' has a similar meaning, but it used more often in written rules and instructions (particularly in British English -- this use is less frequent in American English) and is also used to express your opinion about an action. For example, if we are speaking about a new film and I tell you 'You must see it', this doesn't mean you are obliged to see it -- it's a way that I can express my opinion -- in this case in the form of a strong recommendation.

So in the (B) sentences, both 'must' and 'have to' are possible. 'must' would be particularly common in writing, especially in British English, and 'have to' works as well and has the same meaning.

Hope this helps you make sense of it.

All the best,


The LearnEnglish Team

Thank you very much! These make it all clear. :)

Hello. Is the following sentence OK?
- It is necessary not to play in the street.
Does it mean : You must not play in the street.
Thank you.

Hello Ahmed Imam,

In general, yes, it means that. It's slightly awkward to say 'It is necessary not' to do something, though, because it means you should do something, but that something is not doing something.

I'd suggest using your sentence with 'must' or 'You are not allowed to play in the street' instead.

All the best,


The LearnEnglish Team

Hello. Could you please help me?
Are two modals OK?
- By the ages of five, I (could - couldn't) swim 100 metres.
Thank you.

Hello Ahmed Imam,

Only could is possible here. The phrase by the age of suggests a change and an achievement; not being able to swim is simply a continuation and certainly not an achievement.



The LearnEnglish Team



The LearnEnglish Team

How can i use gerund form and to infinitive with go
I found out in cambridge dictionary that go is used with ing
when we speak about general activities that involve movement
If the activities have a clear beginning and end, then go + to-infinitive is used
I also found out on another dictionary that go gurend used with activities and we donnot use go to inf with activities
In another dictionary we use go to inf to move ot travel place for a particular purpose and they suggest we use shopping or fishing or dancing with go
But why we do use shopping with go ?and not say go to shop or go to dance ot go to watch or go watching
can you explain As for me, they are the same, and I do not understand what these dictionaries mean. How do I know to differentiate between them and use them in a correct way

Hi fdrewaserera,

Most of the time when we talk about activities we use [go + verbing]:

I go swimming every Saturday.

I have to go shopping later because we've got nothing to eat!


It is possible to use [go + to verb] but it generally has a meaning involving travelling to a place in order to perform an action:

I have to go to talk to him this afternoon. [=travel to where he is in order to have a chat]

Paul went to watch the film last night. [=travel to the cinema in order to watch the film]


Go to shop is not a phrase we use. However, you could say go to buy something:

Let's meet tomorrow morning and we'll go to buy some new shoes together.

Go shopping (for something) is much more likely, however.



The LearnEnglish Team

This is really interesting. Thanks.