'Their' usually functions in sentences substantially as an adjective, but technically, "their" is the possessive case of the third person plural personal pronoun. All possessive case nouns and pronouns usually function in a sentence as adjectives, but, since the parts of speech are usually considered mutually exclusive for a single word in a single sentence, it may be important to retain the distinction.
adverb
i want to know what part of speech is camping
what part of speech is beneath
The part(s) of speech that has an "A" sound are: Adjective and Adverb.
Oppose is a verb.
part of speech
The part of speech for this particular word is a noun.
adverb
what part of speech is beneath
The part of speech for "answer" is a noun.
The part of speech for "explicit" is an adjective.
The part of speech for "unfamiliar" is an adjective.
The part of speech for "indefinite" is an adjective.
The part of speech for "lecturer" is a noun.
The part of speech for "breezy" is an adjective.
The part of speech for "buried" is a verb.
The part of speech for "rapid" is an adjective.