SuperflyTNT wrote:
Completely wrong. “Theirs” is a possessive pronoun used to replace the possessive “their” followed by a noun. In this case I used “theirs” in place of saying “their spelling”. “Their’s” is never correct. As a contraction of “their is” it’s just not possible since “their” is always followed by a noun. Now you could have “theirs is” but the contraction would be “theirs’s” and it’s not really a valid contraction.