they
they're theirs, they belong to them
I arrived before them
with/for them
they did it themselves
she fell out with them
they decided it between the two of them
the pupils were talking among themselves
there's a deep rift between them
they were coming the other way
he interceded for them with the king
it won't go down very well
I'm under no obligation to them
there has always been rivalry between them
if we go by what they said …
that incident brought them closer together
they go out in a group, I prefer doing my own thing