Do you want to practise using 'must' and 'mustn't' in English? Play our grammar games and have fun while you learn.

Grammar Rule


I must do my homework.
You mustn’t be late for class.
We must wear our school uniform.


We can use ‘must’ to talk about rules. For the negative, we can say ‘must not’ or ‘mustn’t’.
Parents must take care of their children.
You mustn’t shout in the library.
She must not forget her books.

Be careful!

The main verb is without ‘to’.
He must be careful when cutting food.
I mustn’t make a mess.

We say... We don’t say...

You must look both ways when crossing the road. (NOT You must to look both ways when crossing the road.)
We mustn’t run in school. (NOT We mustn’t to run in school.)
Children must respect their parents. (NOT Children must respecting their parents.)

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Average: 3.6 (907 votes)


That's really easy. I love this web!!!! Is the best!!!!!!

the second one is too easy

yes, it was easy for me too. :)

first game is not working

Hi SapphireFire3000,

Unfortunately some of our games don't work on mobile phones or tablets.

If you're using a computer you may need to update your version of Flash or enable it in your browser. Can you ask an adult to help you? If you still have a problem, please ask them to email us.


Best wishes,


LearnEnglish Kids team

Hi.The first game is not working.

Hi AluminiumMoonstoneCrystal,

The game is working ok for me. You could try using a different browser. If that still doesn't work, you could ask an adult to help you.


Best wishes,


LearnEnglish Kids team

I like it

My name is TuTi

it was easy in the first game I got 10/10 and in the second game I have got 100%............:p