Looking to learn more about compound nouns? Look no further! This article will teach you everything you need to know about compound nouns and how to use them in your writing.
In short:
This guide is part of our free online Grammar Book.
Nouns are naming words, clauses, or phrases that you can use to refer to a person, place, or thing. But what about compound nouns? Grammatically, they serve the same purpose. They're just built slightly differently.
To form a compound word, you take two or more separate words and bring them together to make a new word. The great thing is that you can't only use nouns to make compound nouns; you can also use other parts of speech too. In fact, the combinations are pretty varied.
Here are some of the possibilities:
The thing to remember about compound nouns is that sometimes their meaning can be inferred from individual words (for example, a 'nosebleed' is when your nose bleeds). Still, sometimes the compound noun's meaning is seemingly completely unrelated to the individual word's meaning. For example, a 'shortcake' is not a cake that is short but a particular type of baked, layered cake.
Just like all nouns, compound nouns can be singular or plural; they can be concrete or abstract nouns. They can be possessive nouns, common, proper, or abstract.
When we talk about compound nouns, we are referring to one of three kinds:
Let's look at each of these one by one.
They come in almost any part of speech:
But of course, for the purposes of this article, we'll only be talking about nouns.
Here are some example sentences that use closed compound nouns:
Let's meet at the airport at 9 am.
We use floodlights to illuminate our yard during the nighttime.
I'd love to go swimming but I forgot my swimsuit at home.
Closed compound nouns are the easiest type of compound to pluralize because you just need to follow the usual pluralization rules. This often involves adding an -s or -es at the end of the word, but there are many exceptions to that. You can learn more about these rules in our dedicated article on the topic.
In the meantime, here's what it looks like to pluralize a closed compound noun:
airport → airports
sweatshirt → sweatshirts
snowman → snowmen
toothbrush → toothbrushes
shellfish → shellfish
With open compound nouns, you're still bringing two separate words together to form a new meaning, except when you write them, they stay as separate words. They can comprise a modifier + a noun. For example, 'hot' is an adjective, and 'dog' is a noun,' and together they make the noun 'hot dog,' which is a popular food. 'High' is an adjective, and 'school' is a noun, and together they form the noun 'high school,' a type of educational institution.
Sometimes they're formed with a verb + a noun, like in the word 'heart attack.' Though the term 'heart attack' contains two different parts of speech, a verb, and a noun, together they make a noun.
Here are some example sentences that contain open compound nouns:
Can I have a bagel with cream cheese and salmon, please?
He's old enough to start catching the school bus in the mornings.
Let's meet at the swimming pool at 2pm.
With this kind of compound, it helps to be careful; since they are made up of two separate words, you'll have to use your own judgment to decide whether it's a compound noun or just two separate words. For example, if someone mentions a 'hot dog,' are they referring to a warm animal or a popular food? You'll usually be able to tell based on the context.
Pluralizing open compound nouns can be slightly more complicated because it sometimes involves pluralizing the first word and sometimes the last word.
Take the open compound noun 'washing machine,' for example. The main word here is 'machine' since 'washing' is just a modifier to specify what kind of machine it is. Being a machine is its main trait. So we pluralize the word 'machine' and get 'washing machines.'
washing machine → washing machines
That was a case where the semantic head is the first word. Let's look at a case where the last word is the semantic head. 'Attorney general' is one such example. The fact that they are attorneys is this compound noun's most crucial aspect. 'General' is just a modifier to specify what type of attorney they are. That's why we would pluralize 'attorney' rather than 'general.'
attorney general → attorneys general
The final kind of compound—hyphenated compound nouns—comprises two or more words connected by a hyphen to form a new meaning. A compound noun with more than two words is almost certainly a hyphenated compound noun.
I'm a jack-of-all-trades.
My mother-in-law is coming to visit.
I've been promoted to editor-in-chief!
As Merriam-Webster explains:
Historically, a lot of compounds follow the pattern of entering English as open compounds, then gradually take on hyphenation and eventually a closed form as they become more familiar.
Then you've got words that can be hyphenated, open or closed, like 'lifestyle'/'life style'/'life-style'. Not to mention a lack of clarity around words more recently added to the English language, like words about the internet and computing. 'Email' vs 'e-mail' and 'website' vs 'web site.'
This means there aren't hard-and-fast rules you must stick to, and you have a certain amount of creative freedom. The main thing you want to look out for is to ensure your intended meaning is clear.
The rules for pluralizing hyphenated compound nouns are the same as open compounds: find the semantic head, which is the principal element of the word.
Here are some examples:
take-out → take-outs
passer-by → passers-by
mother-in-law → mothers-in-law
That concludes this article on compound nouns. I hope you found it helpful.
Let's summarize what we've learned:
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