What part of speech is the word that's?

Answer 1

That can be a pronoun (often a relative pronoun), an adverb, or an adjective, depending on the use. Some dictionaries also list it as a conjunction, but I disagree.

Answer 2

That can be a pronoun (often a relative pronoun), an adverb, or an adjective, depending on the use. Some dictionaries also list it as a conjunction, but I disagree.

Answer 3

That's is a contraction of two parts of speech, that (pronoun) and is (verb).