They're There, and They're Theirs!
Looks like we're in that squishy territory again ("Their/there/they're now, Dearie!") with their/they're/there, except that this time we have three to tangle. (Unless you count yore among your and you're, which means that we've been here before. And traversed it!)
Aside: Some people aver that spelling doesn't matter, that all that matters is getting your message across. Strangely enough (and they probably don't even teach it anymore, unless maybe in secretarial school, if such an entity exists), learning shorthand is hard on spelling. It uses sounds—phoneticsThat part of linguistics concerning the written reduction of speech sounds. Not formal phonetics but a good impersonation of it. , actually—to convey the gist of what is said, usually only to the writer of the shorthand, who of course had been there to hear it in the original. Spelling in shorthand is streamlined and contracted, and some of the contractions vary among uses, making it very difficult, if not impossible, for another reader/writer of shorthand to make sense of anyone else's.
And, unless one is very vigilant, it wreaks havoc on spelling.
As does text messaging.
Alas, spelling in English is fraught with inconsistencies and silent letters and double letters and double agents (scratch that) and random foreign intrusions and senseless conventions and rampant clichés. It isn't easy, and it's anything but logical. But it does count.
So even if you are not one who spells well (and there are many, and I have heard and believe that spelling ability is in no way correlated with intelligence), use the spell-checker or the cool eye of delayed proofreading or an exhorted friend to make it right, when it counts. Only you can say when it counts in your life. End of digression.
Their is a third-person-plural possessive
pronounThe avatar for the plural noun (they) has or owns something (the lucky dog) and much more of a mouthful than you were looking for, I'm sure, but unfortunately I can't think of another way to put it right now. Anyway, I notice that the word their must be used in stead of there often enough that, when the possessive pronoun began the first sentence in this paragraph as the subject, and is followed by a singular verb, Word automatically corrects my spelling their to there. That speaks reams (which thankfully are virtual).
Two down and one to go. And it's not neither here nor there.
Recognize that give-away hyphen in they're? We've blown away the a and one space to get the accreted contraction (redundant but hey, because, by definition, a contraction is indeed an accretion).