Their is a possessive pronoun used to describe something belonging to or associated with people or things previously mentioned, or a gender-neutral possessive for both singular and plural subjects. It also functions as a homophone in many dialects of the word 'they’re' (they are) and 'there' (a place or position) in casual speech, which can cause confusion. In standard usage, it modifies nouns (e.g., their house) or serves as a determiner for plural subjects.
Full pronunciation guide
