A contraction is a shortened phrase. He will becomes he’ll, are not becomes aren’t, would have becomes would’ve, and it is becomes it’s. In all of these cases, the apostrophe stands in for the missing letters.
You may find yourself being steered away from using contractions in your papers. While you should follow your teacher’s preference, keep in mind that leaving out contractions can often make your words sound too formal and stilted. (And you shouldn’t eliminate contractions in your papers just to up your word count!)
Possessive pronouns vs. contractions
- your vs. you’re
- its vs. it’s
- their vs. they’re
All three of these pairs are the same kind of pair: a possessive pronoun and a contracted version of a pronoun + to be (you’re = you are; it’s = it is; they’re = they are). These are easy to mix up (especially its/it’s) because—as we’ve learned—an apostrophe + s indicates possession. The best way to use these correctly is to remember that possessive pronouns never have an apostrophe: if there’s an apostrophe with a pronoun, it’s a contraction, not a possessive.
In technical writing, acronyms and numbers are frequently pluralized with the addition of an apostrophe + s, but this is falling out of favor, and there is typically no need to put an apostrophe in front of the s. For example, SSTs (sea surface temperatures) is more acceptable than SST’s when your intention is simply to pluralize.
Ideally, with an acronym or number, use the apostrophe before the s only to show possession (i.e., “1860’s law”; “DEP’s testing”) or when confusion would otherwise result (“mind your p’s and q’s”).
You can also use an apostrophe to stand in for omitted numbers.
It’s important to note that the use of contractions and the use of apostrophes to stand in for omitted numbers are generally considered too informal for most academic writing.
Some students wonder why they should bother learning these rules, then. The answer is that there are plenty of writing situations in which contractions are appropriate. It’s just that contractions are too informal for most of the formal papers you write for college and should be avoided in those situations.