verb

must

muhst

verb

Used to say that something is required or necessary.

"You must show your passport before boarding."

Used to say that something is very likely or almost certainly true.

"She hasn't answered her phone all day — she must be travelling."

noun

Something that is essential or highly recommended.

"Good walking shoes are an absolute must for this hike."

How to Use Must

Learner’s notes

In plain EnglishExpresses obligation ("you must go") or strong likelihood ("that must be true"), or as a noun, something essential.

Common pairings

a must-have must-see you must be joking

Word Forms

must past tense, musted past tense, must plural, mote plural, musts plural, musts plural, must singular, mote singular, motest singular, musts singular

Study it as flashcards or scroll it in Flow — saved to your collection.

Test yourself on “must” A quick quiz — meaning, synonyms & usage →

Fill the Gap

Can you complete this real example?

You _____ show your passport before boarding.

Etymology

From Old English moste, the past tense of a verb meaning "to be allowed or obliged to."

Rhymes for must

bust dust rust lust just oust gust trust crust joust Faust Foust

See all rhymes for must →