You must not smoke here.
- Language
- English
- Level
- B1
- Unit
- Modal Verbs
- Practice types
- 0
What this grammar point covers
Modal verbs for prohibition are words we use in English to say that something is not allowed or is forbidden.
When to use it
Use these forms to tell someone that something is not allowed, for example in rules, laws, or instructions.
Key forms
- "must not" or "mustn't" + base verb
- "cannot" or "can't" + base verb
Examples
You can't park your car here.
Students mustn't use their phones during the exam.
You cannot enter this room.
Tips
- Do not use "don't must" or "mustn't to". The correct forms are "must not" or "mustn't" + base verb.
- "Can't" and "mustn't" both show prohibition, but "mustn't" is often stronger.
- After these modal verbs, always use the base form of the verb (no "to").