Must have vs. Must of

Must have

/mʌst hæv/

An item or thing that is essential or very important to have

Owning a passport is a must have for travelers.The latest edition is a must have for every book lover.A laptop is a must have for college students.

/mʌst əv/

This is a common informal contraction error for 'must have'. It is used when people say words quickly.

It's a must of innovation and creativity.The concert was a must of energy and excitement.Her library is a must of literary classics.

This word has no synonyms

This word has no antonyms

"Must have" is the correct grammatical form, combining the modal verb must with the auxiliary verb have.
"Must of" is a common mishearing or misspeaking of must have, but it's not grammatically correct.
Remember that have serves to form perfect tenses, while of serves as a preposition, and they do not interchange in this context.
Focus on the contraction "must've," which sounds like "must of" but stands for "must have."
Think of have following modal verbs like could, should, and would, unlike of, which follows nouns or after kind or type.