Correct Use
- Compound words are when two or more words are joined, creating a different word with another distinct meaning.
- There are different types of compound words: open (high school), closed (grandmother), or hyphenated (two-fold).
- Compound words include compound nouns (stereotype), compound adjectives (everlasting), and compound verbs (greenwash).
What Are Compound Words?
What do a honeybee, butterfly, earthworm, and jitterbug have in common? That they’re all insects? Nope! That they’re compound words. We’ll teach you everything you need to know about compound words, from what they are to the different types.
Think of the word fire. You might be picturing something similar to flames of bright light, heat, and smoke. Now, think of the word fighter. You’re most likely thinking of something or someone that fights, like a boxer or soldier. Now, put these two words together: firefighter. What do you imagine? A person whose career is to put out and extinguish fires. This is an example of a compound word—two words with separate meanings combined to create an entirely new word.
The LanguageTool Grammar Checker can help you use compound words correctly in your writing.
Types of Compound Words
There are a few types of compound words, including:
These can be written as either open, closed, or hyphenated compounds. Open compounds are compounds that have a space between each word (e.g., full moon). Closed compounds don’t have a space (e.g., daybed), and hyphenated compounds have a hyphen separating each word (e.g., up-to-date).
Compound Nouns
A compound noun is made up of a noun plus another noun. Take moonlight as an example. However, compound nouns are also made using other parts of speech, like verbs and adjectives.
Think of the word haircut. Hair on its own is a noun. Cut is often used as a verb, but when you put those two words together, it becomes a noun again. Please note that the order of a compound noun is not limited to noun + noun, or noun + other parts of speech. Many combinations can produce a compound noun. For example, a verb + a noun can also create a compound noun (e.g., swimsuit).
There are opened, closed, and hyphenated compound nouns. Below are a few examples of each.
(adjective + noun) |
(verb + noun) |
(verb + preposition) |
(verb + noun) |
(verb + adverb) |
(noun + verb) |
(adjective + noun) |
(verb + noun) |
(noun + noun) |
(verb + noun) |
(verb + noun) |
(verb + preposition) |
(adjective + noun) |
(verb + noun) |
(adjective + verb + adverb) |
Often, many words start as open compound words, and eventually turn into closed compound words (e.g., notebook). There are a few standards that can be remembered to know whether a compound word should be opened, closed, or hyphenated. For example, a noun + noun compound word is usually closed (e.g., boyfriend). A compound word that uses a verb + “ing” is often written as an open compound (e.g., dry cleaning).
Compound Adjectives
Compound adjectives are two words joined into one to describe a noun (or compound noun). Like compound nouns, they can contain different parts of speech. Compound adjectives are mostly written with hyphens, but there are also opened and closed forms of these words.
Here are a few examples of compound adjectives:
- Noun + noun + adjective:
Last time she walked by the lake, she saw a seven-foot-long alligator.
- Adjective + noun:
They were in a long-distance relationship for seven years.
- Adverb + past participle:
A new school had to be built because the old one was overpopulated.
Quick Tip
As with most English language rules, the rules for compound nouns and compound adjectives are not set in stone. Knowing when to use what type of compound word takes practice and familiarization. Your best bet would be writing with an easy-to-use spell and grammar checker like LanguageTool. Not only will this writing assistant make sure you consistently use the correct form of a compound word, but it will also conveniently provide synonyms and offer stylistic improvements.
Compound Verbs
There are several types of compound verbs, like phrasal verbs, prepositional verbs, and helping verbs. Here, we are only going to focus on single-word compound verbs. Like in compound nouns and adjectives, these verbs are made by joining two words. Below are a few examples of compound verbs:
I was looking for someone who could babysit my kids for the weekend.
He was notorious for overcooking steaks.
For her birthday, she wanted to test-drive a new Ferrari.
I didn’t want to overstay my visit.
He had to sound-proof his apartment.
Keep in mind that compound verbs are usually written with a hyphen or as a closed compound.
When it comes to compound words, here’s what you should remember: There are many types, like compound nouns, adjectives, and verbs. These can come as open compound words (which have a space between the words), closed compound words (don’t have a space), and hyphenated compounds (the words are separated by a hyphen).
Many compound words have multiple acceptable ways of being written. Sometimes, they start with a space and through years of use, the space is eventually removed. The ambiguity of compound words is what makes them difficult to master. That’s why it’s worth reiterating that you should always have a user-friendly text editor like LanguageTool to help you get the correct spelling (and spacing) of compound words.