Any one out of an indefinite number of persons; anyone; any person.
A person of some consideration or standing.
People; some people; people in general; someone, excluding the speaker.
There (especially as an expletive subject of be).
A single person, previously mentioned, but typically not if previously named and identified as male or female, especially if of unknown or (since 21st century) non-binary gender.
A group of entities previously mentioned.
Their.
The, those.