I don’t usually post about English language grammar, but every so often…
One that bothers me is its and it’s. They confuse a lot of people, and the results of their confusion bothers me. The confusion comes because of the normal rules for possessives — add apostrophe s (‘s) and go from there.
Unfortunately, it is an exception. That’s because pronouns in English can be contracted with some common verbs — is, will, has, have, had, and so forth. Thus he’s, he’ll, he’s (yes, again), he’d, and so forth. The thing is, the possessive for most pronouns is a distinct word. His, her, and their. The exception is it — there is no different word.
So way back in the dawn of time an arbitrary decision was made that either the possessive or contraction get the apostrophe and the other does not. As it happens, another pronoun made the decision a bit easier.
Who. Who is (contracted) versus who possessive. Who’s vs whose. Now I’m aware these two are confused even more. But at least there’s a reasonable expansion that “it” cannot make — the “se” suffix. Again the reasons for decision are lost in the dawn of time, but this time at least we’ve got something that is impossible to use in one case. So ‘s is the contraction and se is the possessive. So there’s at least a hint of uniformity in this arbitrariness, the apostrophe s decision gets carried back to the other exception, and so it’s is the contraction of it is.
Who’s to say whose decisions prevailed. In the end, it’s its own rule, barely shared.
(For those who may have missed the bad pun in the title: link.)