The word "who've" is a contraction, a shortened form of the pronoun "who" and the auxiliary verb"have".
The contraction "who've" functions as the subject and the verb of a sentence or a clause.
Example:
Tickets have been sent to those who have responded.
OR
Tickets have been sent to those who've responded.
The part of speech for this particular word is a noun.
The part of speech that the word my is used as is an adjective.
H is a letter, not a word. To be a part of speech, it needs to be a word.
The part of speech for the word diplomacy is a noun.
The part of speech for the word "boulevard" is a noun.
The part of speech for the word civilian is English grammar.
The word speech is a noun.
It is not ANY part of speech, there is no such English word as "stroobly".
The part of speech for this particular word is a noun.
The word speech is a noun.
The word speech is a noun.
The word speech is a noun.