Before we start talking about this, we need some clarity of language. A hyphen ( – ) is often used to join words together. We’ll talk about those later in this section. A dash ( — ) is a versatile and often dramatic punctuation mark, and since it’s more fun to talk about, we’ll discuss it first.
There are actually two different kinds of dashes. The en dash, which is slightly shorter, and the em dash, which is the one you can see in the previous paragraph. The good news is that the ACT isn’t going to test you on the differences between the two. You will only be tested on the rules of the em dash, which is what we’ll cover here.
There are three major uses for the em dash, and they’re fairly straightforward.
- Use an em dash to show a change in flow in the middle of a sentence. Here, a pair of em dashes set off additional information in the same way commas or parentheses would.
Critics of the Pokémon video game franchise—also known as people who have no fun—say that each game in the series feels exactly the same.
(Note: The difference here is style only, so you won’t have a question on the ACT that will ask you to choose from among dashes, commas, or parentheses. You may be asked to make sure that they are used in pairs or that the additional information really needs to be separated from the rest of the sentence.)
- Use an em dash to introduce an explanation in the same way you would use a colon. Remember: always make sure you have an independent clause before the colon or em dash!
I’m not a big fan of Skyrim—if I can’t figure out where the story is going in the first hour, then I don’t want to play the game!
- Use an em dash to indicate a change in thought or a humorous or dramatic addition to the sentence.
Pac-Man, at its core, is a game about consuming food pellets and pieces of fruit while trying to outrun beings who are out to destroy you—sounds like a typical day in high school to me!
Wait! What About Hyphens?
Oh. Right. I promised you we’d talk about those.
Well, to be honest, the ACT isn’t really going to test you much on hyphen usage. You should know the rules anyway, just in case it comes up, but it’s not one of their favorite topics.
- Use a hyphen to join two or more adjectives together when they act as a single idea and come before the noun they modify
a 5-page paper
a one-year-old girl
an all-too-common mistake
a friendly-looking dog (remember, even though it ends in -ly, “friendly” is an adjective!)
- Don’t use a hyphen when you have an adjective and an adverb before a noun. Adverbs can’t modify nouns, so it’s already clear without the hyphen.
Katie was terribly tired.
Danny was really generous.
- Use a hyphen for all spelled-out numbers from twenty-one to ninety-nine and fractions.
one-third of high school students
- Use a hyphen for most compound last names.
Lady Guinivere Hopkins-Drake will attend the soirée.
- Use a hyphen for some compound nouns.