他们的 in English:

Theirs is an old family.

Isn't that theirs?

A policeman asked the girls if the car was theirs.

Dogs wag their tails and cats swish theirs.

Mary is a big fan of theirs.

Some have come to meet their friends and others to see theirs off.

Our car met theirs near the station.

Some people are good at remembering their dreams, others forget theirs.

Rose, Juniper, Lily, and Camellia were all named after plants, as was Giant Corpse Flower, whose high school experience was far worse than theirs.

Our team triumphed over theirs.

Mister Petro and his wife love my children a lot; I love theirs a lot, too.

Urban foresting was a shared hobby of theirs.

Theirs is a large household; they have six children.

Your team is very good, but theirs is the best.

Their car looks strange. Is it really theirs?