I confess I tend to use a lot of dashes in my writing, mostly in dialogue where a character stops talking in mid-sentence or is interrupted. Both dashes and hyphens can be used to enhance your writing, but there are a few rules you need to follow.
1. The dash can be used to indicate a shift in tone or breaking off of thought.
"How many times have I asked you not to —" Jason suddenly stopped talking and looked out the window.
"Not to do what?" I prompted.
"Not to — Oh heck, I forget!"
2. The dash sometimes separates parenthetical material from the main body of a sentence.
His hopeless condition—it seemed hopeless at the time—caused his wife intolerable anguish.
3. The dash is useful to indicate that a remark at the end of a sentence has been inserted as an afterthought, sometimes with ironic effect.
The president of the firm was a man of absolute integrity—or so it seemed to the stockholders before the firm collapsed.
4. In dialogue the dash can be used to indicate hesitant or halting speech.
“I wish—I wish—I wish,” he said haltingly, as he held his end of the wishbone, “I wish for a vacation in Europe.”
5. The dash is used create drama and emphasis at the end of a sentence.
The film was beautifully photographed, superbly acted, expertly directed—and boring.
6. To clearly set off a long clause or phrase that adds information to the main clause.
“Howard the Duck”—golden boy George Lucas’ one and only mistake—was a box office bomb.
Use dashes for abrupt breaks and added emphasis. Remember that excessive use robs the dash of its power.
1. The hyphen is used to make a compound word out of two or more words which are thought of as a single unit.
She wore a blue-green dress.
He played a better-than-average game.
2. The hyphen is used where a word must be broken (hyphenated) at the end of a line because there is not enough space to write, type, or print all of it. Words must not be divided arbitrarily; they may be hyphenated only between syllables. Avoid hyphenating names whenever possible.
Samuel Johnson, who was an outstanding liter-
ary figure o the eighteenth century in Eng-
land, was known as the great lexicographer.
3. The hyphen is sometimes required to eliminate misreading when a prefix ends with the same letter as the initial letter of the word to which it is added.
re-estimate, co-ownership, de-escalate
4. The hyphen is used in numbers from twenty-one to ninety-nine.
5. Use a hyphen to avoid ambiguities:
A little used car
A little-used car
A little used-car
6. The hyphen is also used to:
Separate dates of birth and death: James Finch (1714-1778)
Scores of games: Princeton-Dartmouth, 78-67
Similar opposing or terminal relationships: sun-moon, day-night, man-woman
Do not overdo the literary device of hyphenating words that are not usually linked: the stringing-together-of-lots-and-lots-of-words-and-ideas tendency can be tiresome.