A compound modifier is two or more words that work together to modify a noun that follows them; essentially, they team up to form an adjective.
Because these words have to be taken together for their meaning to be clear, we generally hyphenate them. If we don't hyphenate them, the meaning of our sentence could become ambiguous.
One way you can tell if two or more words constitute a compound modifier is by removing one of the words to see if the meaning is still clear. Here are examples, with the compound modifiers underlined:
Johnny is a five-time winner of the intramural tennis championship.
How did we know this was a compound modifier? Simple: Johnny can't be a five winner, or a time winner - that wouldn't make sense. "Five" and "time" have to go together for the sentence to make sense.
Here's another one that gets bungled a lot:
As a 10-year-old freshman at Orosi High School, Adelita stands out.
She's not an old freshman, she's not a year freshman and she's not a 10 freshman. This makes sense only when those three words are bundled together.
Now, here's the form of this sentence that gets people:
Adelita, a freshman at Orosi High School, is 10 years old.
Why didn't we hyphenate it that time? Because the rule applies to compound modifiers that precede nouns.
Now, here's the big exception: We don't hyphenate compound modifiers that start with the word "very" or with adverbs ending in -ly, because it's super clear that "very" and the -ly adverb goes with the adjective that follows it. Examples:
Adelita is an extremely pretty girl.
Carmen is a very fast runner.
Brett is unusually tall.
© Holly A. Heyser
