The word they've is a contraction, a shortened form of the pronoun 'they' and the verb 'have'.
The contraction they've functions as the subject and verb (or auxiliary verb) in a sentence.
Example:
They have mailed your refund check.
OR
They've mailed your refund check.
yes theyve kissed
The pronoun in the contraction they've is they, the third person, plural, subjective, personal pronoun. The contraction they've is a combination of the subject pronoun they with the verb have. Examples:They have gone on vacation. Or, They've gone on vacation.They have not had their lunch yet. Or, They've not had their lunch yet.
yes theyve both confirmed it
Nah theyve just got bare attitude!
They go home.
He is scared about where theyve been
They had festivals to celebrate their work theyve dieb
Noo theyve always had Jacoby Shaddix
get seeds plant them in a warm place. when theyve grown, eat them
its becasue he doesnt know where theyve been
yes theyve always been in colour
Of course you can but it's not going to grow back!