Compound Words

When my editor/proofer returned my manuscript of my first book, Dark Tidings, I was surprised to see so many corrections to, what I discovered later are referred to as, compound words. Apparently I had adopted a very ‘relaxed’ style, which meant I had spelt words in the way I felt made it easiest for the reader. I actually liked the style, but my publisher wanted formal spelling rules to be followed.  This was quite traumatic because it meant I had stop writing the sequel so I could check all the compound words in Dark Tidings. I needed to research the subject first, and learn the rules.

Compound words can be used as nouns, verbs, adjectives, or adverbs and can be spelled as one word, two words, or hyphenated. So in essence there are three forms of compound words:

  • closed form – words are simply melded together e.g. corkscrew
  • open form – words are separated by a space (so it’s not really a compound word) e.g. full moon
  • hyphenated form – words are separated by a hyphen or hyphens e.g. six-pack, son-in-law.

I discovered that there are twenty-one (numbers are always hyphenated) rules of thumb (that’s how you pluralise an open form compound word) to determine which form the compound word will take. Of course, because we’re talking about English so there are loads of exceptions and sub-rules and just to complicate things a little e.g. it sometimes depends on how the word is used and where it appears in the sentence.

For general rules, I found it was easiest to look at word types.

Adjectives (modifiers)

Hyphenate two adjectives united to modify a noun, except when the modifier comes after the noun e.g. curtains which are fire resistant are called fire-resistant curtains.

Having said that, there is a convention to use open compounds for words which are deemed to form perpetual concepts e.g. an ice cream cone.


Don’t hyphenate ‘-ly’ words to the verbs they modify e.g. a brightly coloured shirt. Hyphenate other adverbs to their verb e.g. my best-kept secret (although compounds with the words ‘least’, ‘less’, ‘most’ and ‘more’ are exceptions, so are not hyphenated).


Nouns usually adopt the closed form e.g. blackboard, fingerprint if the word is well accepted. However, some words you’d expect to be ‘accepted’ aren’t so they take the open form e.g. body blow. Compounds which can be used as verbs and nouns differ in that the verbs are usually hyphenated while the nouns aren’t e.g. we’ll need to  jump-start the car, because the car needs a jump start. Another example is fast track. We fast-tracked the project, but the project is on the fast track.


Compound verbs are generally hyphenated e.g. stir-fry, kick-start, although where the verb is well accepted it can adopt the closed form e.g. to sleepwalk.

Multi-word Compounds

Multi-word compounds always include hyphens e.g. right-of-way, up-to-date. Always? You’re right, that would be too simple. Common expressions which do not appear in the dictionary don’t have hyphens e.g. head to toe, unless they are being used as modifiers e.g. a head-to-toe inspection.

That was five of the rules sorted (more or less), only sixteen more to go. As you can imagine, it took me a while to feel I had a proper handle on the ‘basics’ but with a bit of time and effort I made it. So now, with handle firmly grasped, I can write my books without the worry of revisiting (not re-visiting) the whole text later. A word of warning though, have a good dictionary to hand at all times because the rules don’t always give you the right answer.

I hope this post has convinced you that you should add compound words to your checklist of things to look out for when you proofread your finished text, or at least make sure you spot-check a good number of them on the way through. Out of interest, do you think the compound words in this paragraph are right or wrong?

I try and keep these three examples in my head:

  • it’s just common sense to adopt a common-sense approach (the spelling depends on whether the word is being used as a noun or an adjective)
  • a PC used for word processing will usually run a word-processing package (the spelling depends on whether the word being used as a verb or an adjective)
  • he gave me on the rundown on the run-down Victorian house (the hyphen changes the meaning of the word)

They remind me that compound words are tricky. So if I’m not confident after I’ve written one, I look it up in the Oxford English Dictionary. And, before you ask, this post relates to UK English. The US English rules are similar although there are some subtle differences.

That’s my confession, what about you? What type of words do you always struggle to spell?

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