MUST VS HAVE TO (A2 Grammar)

MUST and HAVE TO = obligation. But MUSTN'T and DON'T HAVE TO are very different!

Quick tip: MUSTN'T = forbidden! DON'T HAVE TO = not necessary/optional. Very different!

MUST/HAVE TO: obligation (necessary)

Both mean it's necessary. Must = personal. Have to = external rule.

• I must finish this today.
• I have to work tomorrow.
• You must wear a seatbelt.
• She has to study for the exam.

MUSTN'T: forbidden (NOT allowed)

Mustn't = prohibited, not allowed. It's against the rules.

• You mustn't smoke here.
• Students mustn't cheat.
• You mustn't park there.
• You mustn't touch that!

DON'T HAVE TO: not necessary (optional)

Don't have to = not necessary. You can choose. It's optional.

• You don't have to come.
• She doesn't have to work tomorrow.
• We don't have to wear uniform.
• You don't have to buy a ticket.

Common mistakes

• Not "You mustn't come (meaning: it's optional)" — say "You don't have to come". Optional = don't have to, not mustn't.
• Not "She doesn't have to smoke in school" — say "She mustn't smoke in school". Forbidden = mustn't.

Practise it

Forbidden? = MUSTN'T. Not necessary/optional? = DON'T HAVE TO. This is important!