Confusing wordsGrammar

Compound word nightmares: open, closed, or hyphenated?

From Rick:

I don’t know about you, but as a writer and an editor, I’m constantly beset with problems when dealing with compound words: should it be one word, two words, or a hyphenated word? We all know that “bedroom” and “bathroom” are one word. But is it “bath house” or “bathhouse”? (It’s one word.)

When you trade in your old car, is it then a “trade in” or “trade-in” or “tradein”? (It’s hyphenated.)

What makes matters worse is that not all dictionaries will agree on the form, and if your dictionary is a little older, you may find some forms different from those in a newer version of the same dictionary.

In the first edition of Punctuation For Fiction Writers, it was pointed out that, while most dictionaries now showed “sweatshirt” as one word, the online Merriam-Webster dictionary (M-W) at the time (2015) still showed it as “sweat shirt.” I’ve seen older dictionaries that listed the intermediate form “sweat-shirt.”

As a side note, the current M-W online now has it as one word. I’ve removed that note from the 2nd edition of the punctuation book. I know I’ve been promising the 2nd edition of that for a couple of years, and I’m getting there. Trust me that the revision will be worth the wait.

Before I continue, let’s define a couple of terms that apply here to compound words.

COMPOUND NOUN: a noun consisting of more than one noun (bathroom) or a noun plus adjective (whiteboard, washing machine, six-pack).

COMPOUND VERB: a verb consisting of two words; both can be verbs (stirfry) or one can be a noun (babysit). Note that the term “compound verb” has other grammatical meanings, such as any verb that has an auxiliary verb with it (was walking, has walked, will walk, can walk, should walk). They can also include verbs plus a preposition (ask for) or phrasal verbs (take away), but those aren’t our concern here. I talked about phrasal verbs back in two of the April posts, which you can use the blog’s SEARCH box to locate if you need a refresher. Here, I’m only interested in the first definition I gave for compound verbs.

OPEN: the compound is two words (living room)

CLOSED: the compound is one word (bathroom)

HYPHENATED: the two words are joined by a hyphen (decision-making)

For more info on the uses of hyphens, try the link below. It’s a good cheat sheet (and note that “cheat sheet” is an open compound):


Now that I have that out of the way, you’re probably hoping that I’m going to give you some rules or guidelines on how to know which compounds are open, closed, or hyphenated. I only wish I could.

Sadly, there are few rules other than those in the hyphen article I just gave you. What’s worse is that the landscape is constantly changing. Some compounds that only a few years ago were open or hyphenated are now closed, while others that we might expect would be closed (like “cheat sheet”) are not yet. I’m seeing “cellphone” as an alternative spelling in some dictionaries (including M-W), but the closed form is not yet fully established.

While I cannot give you any good rules, I can give one strong good piece of advice: do NOT trust MS Word’s spell checker! It falsely shows some compounds as closed while some closed ones it wants open or hyphenated, and much of the time it will accept hyphenated words without complaint even if they’re wrong. For example, it flags “step-son” as incorrect because it should be closed (stepson), but it does not flag the hyphenated “step-sister” as wrong (which also should be closed). And the previous versions of MS Word consistently flagged “stone wall” as incorrect even when it meant a stone wall, instead thinking it should be the verb “to stonewall.”

However, during my recent editing jobs, I have been compiling a list of common compound words that include nouns, verbs, adjectives, and adverbs. I have made it a downloadable MS Word .doc file that you can save or print. I will be updating it as I come across other common words, and you can certainly add your own favorite words to it.

Using this list will save you some time looking up words in the dictionary. For me it’s not as much of a time-saver when writing as it is when editing, where efficiency is important.

Note that on the list I show the part of speech of the compound where relevant because the form of the compound may differ with the usage.

That’s a flat-out lie. (adjective)
He is flat out wrong. (adverb)

You can access the list from the blog’s MENU under the RESOURCES tab.

I hope you find the list useful.


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