it’s vs. its

One of the most common spelling mistakes in all of English is to use an apostrophe with the word its when we want to indicate possession, or to omit the apostrophe when writing a contraction of it is or it has.

We usually express possession in writing by adding ’s to the end of a noun, as in Mary’s, John’s, the council’s, the dog’s, etc. (As a matter of fact, this possessive ’s is technically a contraction as well, stemming from the Old English suffix “-es”; however, this “-es” ending fell out of use, and we generally think of the possessive ’s as a distinct syntactic and grammatical construct of its own.)

Curiously, the possessive form for the personal pronoun it does not have an apostrophe, just an S—its. However, the possessive form was originally spelled it’s, with the apostrophe. This was dropped around the 1800s, most likely due to the established prevalence of the contraction of it is.

In any case, we can only use ’s with it when it’s is a contraction of it is or it has. If we write its, we are indicating gender-neutral possession for an object, animal, group, etc.

Let’s look at a few examples just to see the difference more clearly: