Hyphens can be a bit tricky. And they shouldn’t be confused with dashes, which have a completely different purpose. The hyphen on a keyboard is located between the number ‘0’ key and the ‘=’ key. See below for examples on how to use hyphens.
The Five Uses
-to create multiple-word adjectives
-to write out compound numbers
-to avoid confusion or an awkward combination of letters
-with certain prefixes and suffixes
-for line breaks (yuck)
Multiple Word Adjectives
If the words modify a single noun and they come before a noun, they need to be hyphenated.
I just at a delightful, sprinkle-covered ice cream cone.
She tends to prefer fast-paced basketball games; I care more about the defense.
But if the adjectives come after the noun, no hyphen is needed.
The ice cream cone was sprinkle covered.
All two-digit numbers above 20 (except those ending in ‘0’ like 30, 40, 50, etc.) need hyphens to connect the numbers.
She was only eighty-seven when she passed away.
Avoid confusion or awkward combinations
Some words look like they mean something else without a hyphen. If you have a prefix or suffix that makes the word confusing, add a hyphen. If two words end and start with the same letter (and it looks weird), add a hyphen.
Re-create vs. recreate
Re-sign vs. resign
semi-independent vs. semiindependent
shell-like vs. shelllike
With certain prefixes and suffixes
Some prefixes and suffixes always need a hyphen. Here’s a list of the most common:
prefix-Capitalized word (anti-American)
figures or letters (T-shirt; mid-1990s)
For line breaks (but nobody likes line breaks anyway)
When a word at the end of a line (like in a book or column in a magazine) is too long to fit, many desktop publishing programs hyphenate the word, breaking it in half. But hyphenating line breaks is bad design and decreases readability. So just avoid it.