1. Comma usage

2. SEPARATE WORDS IN A SERIES
Henry Ford Ii High School focuses on academics, sports, and the fine arts. This year my employer promises to provide more breaks, to give raises, and to reimburse for gas and mileage.

3. Separate 2 coordinating adjectives
He was a difficult, stubborn child. She wore a gray wool shawl. The waitress has an easy, happy smile. They lived in a white frame house.

4. separate independent clauses in a compound sentence
The game was over, but the crowd refused to leave. Yesterday was my birthday, so we went out for dinner. He asked the question, yet she did not understand.

5. Separate subordinate introductory clauses
While I was eating, the phone kept ringing. If you are ill then go see a doctor. When the summertime arrives, we will open the pool.

6. Separate an introductory word
No, our crew was unable to call for help. Eventually, a ship spotted us. Hey, what’s that in the water over there? Well, I wouldn’t call it the film of the century. Fortunately, the tow-truck came soon to save us.

7. Separate tell-tale phrase note: only use a comma to set-off the phrase is in the beginning or middle of the sentence

8. Set-off INFINITIVE PHRASES
To get a seat, you must come early. To find the bus depot, we had to walk for miles.

9. Set-off Participles & participle phrases
Laughing, he fell off the lawn chair. Racing from the cops, she crashed her car.

10. Set-off prepositional phrases
Before dinnertime, I went swimming. On top of the car, we strapped down our Christmas tree.

11. Set-off appositive phrases
Karen Trivelloni, HF II English teacher, teaches reading and writing. The HF II English teacher, Karen Trivelloni, teaches reading and writing.

12. Parenthetical expression
Danny did, of course, keep a journal. He took notes, I believe, on several previously unknown species.

13. Comma abuse Don’t use commas to separate the subject from verb
Error: A ball player, is skilled at hand-eye coordination.
Don’t use commas between two verbs (this is not a compound sentence)
Error: I turned the corner, and ran into a police officer.
Don’t put commas between two nouns (need a series of 3 or more)
Error: The music teacher, and the football coach are friends.