The word mustn't is a contraction, a shortened form for the verb (or auxiliary verb) 'must' and the adverb 'not'. The apostrophe takes the place of the missing letter 'o'. The contraction functions as a verb (or auxiliary verb) in a sentence. Example:
We must not be late for school. Or, We mustn't belate for school.
adverb
what part of speech is beneath
i want to know what part of speech is camping
The part of speech is a adjective
Oppose is a verb.
The part of speech for this particular word is a noun.
part of speech
The apostrophe takes the place of the deleted O in "mustn't" (must not).
The part of speech for "answer" is a noun.
what part of speech is beneath
adverb
The part of speech for "explicit" is an adjective.
The part of speech for "lecturer" is a noun.
The part of speech for "rapid" is an adjective.
The part of speech of "came" is a verb.
The part of speech for "breezy" is an adjective.
The part of speech for "buried" is a verb.