The Comma with Two or More Adjectives

I bought a fast, red car.

The Comma in Compound Sentences
fanboys (for, and, nor, but, or, yet, so)

Marilyn ran for office, and she won easily.

The Comma in Complex Sentences

When the tide went out, the men dug clams.
The men dug clams when the tide went out. (no comma if independent clause is first)

The Comma for Items in a Series
Use commas to separate items in a series, whether the items are words, phrases, or short clauses.

Alice ordered folders, stationary, and stamps.

The Comma with Interrupters
Commas set off words that are not part of the main structure of the sentence.

You know, of course, that his job is in jeopardy.
Yes, I understand now.