Compound Words

Baseball, hot dogs, and apple pie: three words near and dear to many American hearts. Actually, the words have more in common than Americana; they are members of a category of words called compound words.

What are Compound Words?

Compound words are formed when two or more words are put together to form a new word with a new meaning. They can function as different parts of speech, which can dictate what form the compound takes on. For example, the word carry over is an open compound word when it’s used as a verb but it is closed when used as a noun and an a adjective.

This surplus will carry over to next season.
The extra supplies were part of the carryover from the budget.

Compound words are so prevalent in the English language we don’t think much about them – until it’s time to write them. Then we often have to stop and think about how they’re put together.

Examples of Compound Words

Compound words fall within three categories and it’s not unusual to find the same word in more than one group. Here are the three types of compound words with an explanation and examples of each:

Closed compound words are formed when two unique words are joined together. They don’t have a space between them and they are the type that generally comes to mind when we think of compound words. For example:

Cannot Baseball
Fireworks Grandmother
Elsewhere Upside
Together Sunflower
Crosswalk Become
Basketball Moonlight
Football Railroad
Anybody Weatherman
Skateboard Earthquake
Everything Sometimes
Schoolhouse Upstream
Fireflies Grasshopper
Inside Playthings


I love the fireworks on the fourth of July.
Make sure you hold hands when you come to the crosswalk.
The ocean was bathed in moonlight.
Did you hear amount the terrible earthquake?
The fireflies buzzed in the night sky.

Open compound words have a space between the words but when they are read together a new meaning is formed:

Ice cream Grand jury
Cave in Post office
Real estate Middle class
Full moon Attorney general
Half sister


Ice cream is my favorite dessert.
The line at the post office snaked all the way out the door and around the corner.
Rhonda is my half sister.
There must be a full moon out tonight.

Hyphenated compound words are connected by a hyphen. To avoid confusion, modifying compounds are often hyphenated, especially when they precede a noun such as in the case of part-time teacher, high-speed chase, and fifty-yard dash. When they come after the noun they are open compounds: a chase that is high speed, a teacher that is part time, etc. Comparative and superlative adjectives are hyphenated when they are compounded with other modifiers: the highest-priced computer, the lower-priced car. Adverbs that end in –ly and compounded with another modifier are not modified: a highly rated restaurant, a publicly held meeting.

Here are more examples of hyphenated compound words.

One-half Mother-in-law
Eighty-six One-third
Merry-go-round Well-being
Mass-produced Over-the-counter


My mother-in-law is coming for a visit.
The merry-go-round at the carnival thrilled Ella.
Some over-the-counter drugs can have serious side effects.

If you’re concerned for your well-being make sure you eat healthy foods and get plenty of exercise.

It’s true the rules for compound words can be a bit ambiguous at times. The best thing to do when you have a question about a compound word is look it up. Often times you’ll find options with the preferred choice listed first. The bottom line is that the only way to know for sure how to spell compounds is to consult an authoritative source: a good dictionary.