1. Hyphenated words

2. Rule #1
Hyphenate all compound numbers from twenty-one through ninety-nine.
Examples: The teacher had thirty-two children in her classroom. Only twenty-one of the children were bilingual.

3. Rule # 2 Hyphenate all spelled-out fractions.
Examples: You need one-third of a cup of sugar for that recipe. More than one-half of the student body voted for removing soda machines from campus

4. Rule # 3
Hyphenate all words beginning with self except for selfish and selfless.
Examples: self-assured self-respect self-addressed

5. Here are some other examples:
Vice-president
School-poet
Student-athlete
Brother-in-law
Great-granddaughter
Self-restraint
One-half
President-elect

6. Use Hyphens to connect two or more words into a new adjective
A one-way street
Ice-covered trees
Tree-lined streets
Just-baked cookies
Vanilla-flavored milk
A once-in-a-lifetime event