Commas with coordinating conjunctions: This is a review of our discussion of comma-spliced and run-on sentences. Whenever two sentences are joined with a conjunction (one of the FANBOYS), always use a comma and then the conjunction.

Example:

Walking home from school can be fun, but I prefer driving my '64 Chevrolet coupe.

Commas with introductory words, phrases, or clauses: We discussed commas used with introductory dependent clauses, prepositional and participial phrases, and introductory words when we discussed fragments.

Example:

Because I was sick, I stayed home.

Commas with items in a series: When listing items in a series, place a comma after every item in the series, including the item right before the conjunction.

Examples:

I like broccoli, carrots, beets, but not asparagus.

My mother bakes great cookies, cakes, and pies.

Commas with interruptors: Phrases that interrupt the natural flow of a sentence or that give additional information not necessary in order to understand the sentence are also set off by commas.

Examples:

"I am always tired," he said, "because I just don't get enough sleep."

The moment for questions about the test, however, is past now that the exam has begun.