No, I couldn't care less!
No, "theirs" is a possessive pronoun that does not require an apostrophe to show possession.
That there is theirs. I'm certain that the piece of luggage is theirs.
that bird is theirs.
The books are ours.
The dessert is theirs. Decide whether you want to watch pets in your home or theirs They are as curious about our culture as we are of theirs
The treehouse was theirs, and no one else's.
The duration of Theirs Is the Glory is 1.37 hours.
There is only one syllable in the word "theirs".
It's a fine distinction, but the context would be important. In many cases, saying, "It is for them" means it will be theirs but it is not theirs yet.
Theirs not to make reply Theirs not to reason why Theirs but to do and die Into the valley of death rode the six hundred
theirs they themselves
Because it WAS theirs. See related question.