Hyphens are easy...and confusing. I’ll try to cover the basic rules, but after that, you have to do your homework--use your dictionary.
Part of the reason for the confusion is that English is always changing; a compound word that began its “career” as two words, may progress to a hyphenated word, and finally evolve into a solid word.
We sleep in bedrooms. Bedroom has arrived at its final destination: a single, solid, compound word.
But we still have dining rooms. (Two words.)
A decision may be far-reaching, but a forecaster is farseeing.
Check the dictionary if you are unsure, but many compound words are “made for the occasion,” such as the word I used in my “Wow” story. Dust-crusted. It will not be in the dictionary. My spell check is telling me the hyphenated form is correct, but the solid word is not.
The stylebook of one publisher says, “If you take hyphens seriously, you will surely go mad.”
There is a logic, however, so I’ll highlight that, mention the pitfalls, and then you’re on your own.
1. Compound numerals are written with a hyphen: thirty-one, sixty-eight.
2. Fractions are written with a hyphen IF they are being used as an adjective:
The marmalade was one-half sugar and one-quarter oranges.
BUT..... One half of the marmalade was sugar.
3. Compounds with self are written with a hyphen: self-centred, self-conscious.
Exceptions = selfless, selfhood, selfsame.
4. Expressions of family relationship use hyphens: great-grandmother, step-mother, great-uncle.
5. MOST compounds beginning with the prefix ex, pre, and pro use a hyphen: pro-life, pre-Columbian, ex-husband.
6. Compounds using prepositional words use hyphens: mother-in-law, one-on-one, heart-to-heart.
7. Compound modifiers for nouns use hyphens: well-cooked potatoes, five-year-old child, midnight-blue dress.
BUT... only when the modifiers come directly before the noun. If they don't, the form changes.
The steak was well done. However.... She enjoyed her well-done steak.
8. Use a hyphen in a “coined” or “occasional” compound, a "made-for-the-occasion" compound: wind-fuzzed, smoke-laden
She gave him a what-do-you-think-you’re-doing look.
9. Hyphens are used in compounds that name the same person in two different capacities: author-illustrator, pastor-counsellor, butcher-chef
10. A hyphen is used to avoid clumsy spelling: bull-like (not bulllike) semi-independent (not semiindependent) pre-empt (not preempt).
11. The hyphen is used at the end of a line to indicate the division of a word. Remember how to properly divide syllables!
Proper: con-tin-ued, in-di-cate
Improper: wo-rd, comp-ound
A funny about this... I was reading a book a couple years ago about the Inuit in northern Canada. The line said something like this with the division splitting the word and hyphenated as I’ve written it:
Nanook used the snowk-
nife to slice the snow into blocks.
I read that probably twenty times, trying to figure out what in the world was a snowk... or snowknife. Improper division... it should read snow-knife.
Be careful when using the prefix “ex.”
The banquet honoured ex-Social Credit Premier Bill Van der Zaam.
Is Bill no longer Social Credit? (political party in Canada)
Correct: The banquet honoured the former Social Credit Premier Bill Van der Zaam.
I met his cousin, an old sewing machine collector.
Is the cousin old? Or does she collect old sewing machines?
Correct: I met his cousin, an old-sewing-machine enthusiast.
Use a hyphen to avoid confusion.
Marie recovered the old wing chair. (The appropriate word is re-cover.)
They enjoyed the recreation of the Battle at Little Big Horn. (The appropriate word is re-creation.)
Another word to watch for is re-claim vs. reclaim.
Credit to "Correct Writing," Second Edition, DC Heath and Co., Lexington, Massachusetts, 1980.
"What remains of a story after it is finished? Another story..." Eli Wiesel