Mechanics - Punctuation - Commas
Use commas to separate a series of three or more short clausesA clause is a group of words having a subject and a verb. Source: Lesson 246.
I am working, he is sleeping, and she is singing.
(The comma before the conjunctionA conjunction is a word that joins other words, phrases (groups of words), or clauses (groups of words with a subject and verb). Source: Lesson 78 and is optional, but I prefer using it.)
Use no commas in a series when all items are joined by or, and, or nor.
Instructions: Place commas where they are needed.
1. They are eating we are drinking and you are starving.
2. The music began the lights dimmed and the curtains opened.
3. My sister has left home my brother is at school and my mother is baking bread.
4. Jim fished Jeff hiked and I loafed the whole campout.
5. You correct he proofreads but I edit material.