Grammar Reference must – mustn't – can't

Grammar Reference: must – mustn't – can't

This section explains the difference between 'must', 'mustn't', and 'can't' in English.

• can't: Used for refusing permission. Example: You can't play loud music at night. (You aren't allowed to)
• must: Used for obligation. Example: You must keep the room clean and tidy. (That's the rule)
• mustn't: Used for prohibition. Example: You mustn't eat in class. (It's forbidden)