How (and When) to Use a Hyphen
What is the Point of Hyphens?
Think of using a hyphen as using a piece of tape for two words: it sticks them together. Usually, the purpose of a hyphen is to create a compound word of some kind. But why would you want to create a compound word?
Compound words can often help to clarify the meaning of a sentence. Writing clearly is very hard--even for seasoned writers--because you already know what you mean, don't you? How can you tell whether what you wrote makes sense to someone else?
That's where grammar rules come in. Hyphens are just one little way to say what you mean to say, and to say it clearly.
Table 1. Common Prefixes
Table 2. Suffixes that Use Hyphens
When to Hyphenate
- Use a hyphen with prefixes. Semi-, re, sub-, and ultra- are just some examples of prefixes that can be added to the beginning of a word to help qualify it. In most cases, use a hyphen when simply adding on a prefix. See more examples of prefixes in Table 1.
- Use a hyphen with a prefix to clarify a word. Using a hyphen with "re-" is often necessary to indicated that something has happened again. For example, you might re-save a document. It needs a hyphen because "resave" is hard to read.
- Use a hyphen to describe familial relations. Great-grandmother and step-sister are great examples. This may take memorization.
- Use a hyphen to create an adjective with a suffix. If something is like an octopus, but isn't an octopus, you can add "-like" or "-esque" to make octopus-like. Table 2 contains a few examples.
- Use a hyphen to combine adjectives with nouns to create an adjective. For example, That is due to small-town politics. Here, small-town is used as an adjective even though it contains a noun (town). However, the phrase, "I live in a small town," does not need a hyphen.
Hyphens with Numbers
- Hyphenate fractions if all of the numbers are spelled out. One-third of the people here have brown hair. Three-fourths of my coffee cups are chipped. However, don't hyphenate fractional phrases that start with "a" or "an." A half, a third. Similarly, don't hyphenate phrases that indicate a fractional amount without using the number. One quarter of the wall is painted.
- Hyphenate all numbers twenty-one through ninety-nine, always. I am thirty-two. This is ninety-five inches long.
- Hyphenate ranges. The meeting will be 9-9:30 a.m. I expect 70-80 people to come.
Table 3. Phrases that Often Abuse Hyphens
Hyphens as a Style Choice
Using hyphens with adjectives and nouns can be a style choice, but there are correct and incorrect ways to use hyphens.
Whether or not to use a hyphen within certain grammatical constructions is not the style choice, however; the arrangement of the sentence is.
For example, consider the sentence:
That cupcake looks yummy.
Now, look at this sentence:
That is a yummy-looking cupcake.
These two sentences have the same meaning, don't they? The speaker thinks the cupcake looks like it would taste good. However, the grammatical construction of the second option creates a difference in tone, which is a style choice.
As another example, consider the sentence:
The nine-year-old splashed through the puddle.
That sentence is fun and image-driven. Compare it to:
The child, who is nine years old, splashed through the puddle.
The difference, again, is in tone. In this case, the tone difference is stark enough that it almost gives the two sentences separate meanings. And, depending on the sentences around them, they might actually have two different meanings. The first example is fun and sets the scene, focusing on the age of the child. The second sentence is more explanatory, almost as if the speaker is mentioning the age of the child as an aside.
Tip: The "Add 's'" Rule
To help you decide whether to use a hyphen, add "s." If the "s" won't fit, the phrase could use a hyphen.
For example, think about describing someone's age. Both "one-year-old" and "one year old" are correct. How can this be? It depends where it is in the sentence. "One-year-old" (with hyphens) is a phrase that has been connected to function as one word. "One year old" (without hyphens) is a phrase that functions as more than one word. For example:
She is a one-year-old.
She is one year old.
One helpful way to think about this common conundrum is to add "s." For example, "she is a two-years-old" doesn't make sense, but "she is two years old" definitely does. "Two-year-old," then, functions as a noun. You could replace it with other nouns, like, "she is a lioness," or "she is a wizard." You can't replace the phrase "two years old" with another noun unless you add an article (a or an).
As another example, if you have to write a 7-page paper, you may notice your teacher put a hyphen between the number and the word "page." Try the "add 's'" rule again: You have to write a 7-pages paper. Doesn't quite sound right, does it? No, you'd write a paper that is seven pages long, with no hyphen. If the "s" doesn't fit, then a hyphen helps the phrase.
Tip: When in doubt, flip it around.
If you're not sure whether or not to use a hyphen, get yourself out of that situation! That doesn't mean you should abandon the assignment, nor does it mean you should indiscriminately remove hyphens from the piece. To do that, put the hyphen-in-question phrase in a different place in the sentence without losing the meaning of the sentence. For example, knowing whether to hyphenate the common phrase "concealed weapons" can be tricky. Your first instinct may be to write:
Do you have a concealed weapons permit?
Without a hyphen, "concealed" and "weapons" actually describe "permit." But, as we should know, this phrase is not referring to the ability to see the permit; it's referring to ability to see the weapon. So, one way to eliminate confusion is to rearrange it to read:
Do you have a permit for concealed weapons?
Of course, if you're comfortable with your hyphen skills, you'll be able to place the hyphen between the words "concealed" and "weapons" with confidence.