Even if you’re in the know, these tricksters can get by you
Some mistakes in English usage are simply easier to make than others, and even experienced writers make them from time to time, especially when they are in a hurry.
Consider, for example, confusion over homophones — in particular, it’s/its, they’re/their*, you’re/your, and who’s/whose. In each case, the words sound identical but have different meanings.
The first word in each pair is a contraction, shorthand for the expressions it is, they are, you are, and who is. The apostrophe in contractions, as we all know, is placed where letters have been omitted.
The second word in each pair is a possessive pronoun.
Homophones are simple, right? Wrong.
We know we need apostrophes in contractions, but we also know that apostrophes are often used to indicate possession.
“Why is it,” the frustrated writer may be justifiably tempted to ask, “that possessive pronouns don’t need apostrophes? After all, when we make names possessive, we use an apostrophe: “Maddie’s glove,” “José’s car,” “Sean’s house,” for example.
It helps to remember that possessive pronouns don’t need apostrophes because they are already possessive.
In our examples, we needed apostrophes with Maddie, Jose, and Sean to show possession because those proper nouns can also be used in other contexts; that is, sometimes those nouns aren’t possessive. When they are possessive, we need a way to signal that shift to the reader.
Possessive pronouns, in contrast, have no other function except to show possession, so apostrophes aren’t necessary.
Not all possessive pronouns tempt us to insert an apostrophe. Consider my, mine, our, her, your, and his, for example—no temptation there.
But the ones that sound exactly like commonly used contractions give us the most trouble because our mind plays tricks on us: First, we see the contractions often enough that the apostrophe looks normal. Second, we know we need a possessive pronoun. Third, we associate the possessive case with apostrophes.
And so we insert an apostrophe where none is needed.
To avoid making this common mistake, any time we are tempted to insert an apostrophe in these four words, take a moment to ask if the uncontracted construction (it is, they are, you are, or who is) would work in its place.
We would never say, for example, “The shiny bauble has lost it is luster,” so we shouldn’t write “it’s luster.”
Likewise, in the construction “You’re right,” you’re can logically be replaced with “you are,” so the contraction is the right choice; we should avoid writing “your right.”
Intellectually, most writers understand the difference between most common homophones, but when we are in a hurry, typing with our thumbs, or dashing off a quick comment or text, it’s (it is—check!) easy to get confused.