If you’re like me, you could use a refresher on the proper use of commas. I hope you find the following examples helpful in your journey to grammatical correctness.

Use a comma when a conjunction separates independent clauses (independent clauses  express a complete thought and can stand on their own). For example :

Amy and Shaun attended their 15th high school reunion, and they were thrilled to see that many of their former classmates had gotten fat.

If the subject does NOT follow the conjunction, omit the comma. For example:

Amy and Shaun stole expensive outfits and planned to return them after the reunion.

When the conjunction and is followed by the word that, no comma is used unless that is used as the subject. For example :

No comma :

Shaun was sure that Amy was unaware of his affair with Jill Peterson and that she would never  find out.

 Comma :

Shaun could not have been more mistaken, and that was the reason for his black eye and swollen lip.

No comma is needed to separate compound subjects that refer to the same verb or compound verbs that refer to the same subject. For example :

Amy and Shaun yelled and screamed about the alleged transgression with Jill.

 In the above example, Amy and Shaun is the compound subject, yelled and screamed is the compound verb, and Jill is  a tramp.

Commas are needed if a dependent/subordinate clause (a phrase that is an incomplete thought) appears at the beginning of a sentence and it is NOT the subject of the verb. This is an introductory clause. For example :

Although Jill is a tramp, she is not the only guilty party.

A comma is usually not needed when the dependent clause appears at the end of a sentence. For example :

Jill is in for a thrashing from Amy if she is not careful.

No comma is needed when the dependent clause is the subject of the verb. For example:

To cheat on a woman who knows karate is unwise.

Commas are needed to offset unnecessary words (parenthetical expressions) at the beginning of a sentence. For example:

As a matter of fact, it is unwise to cheat on any woman who has access to your bank account.

Commas are needed to offset parenthetical expressions that interrupt the main thought but are nonessential. For  example :

Shaun noticed Amy looking seductively at Brad, who had been the school’s quarterback and was dumb as a brick, and he wondered what was up with that.

Use commas to separate three or more items. For example :

Brad had always been arrogant, unintelligent, and quite greedy, so it was unsurprising that he was now a member of Congress.

Don’t use a comma to separate only two items.

Amy was also trampy and deceitful.

 Commas are used to separate two or more adjectives that modify a noun. For example:

The angry, devious woman was a hypocrite.

Tip – You can identify two consecutive adjectives by mentally inserting the word and between them. Amy was angry and devious.

Commas are generally needed with appositives. An appositive is a word or phrase that describes the noun preceding it. For example:

Shaun, a man who can only be described as delicious on the outside and hollow on the inside, couldn’t decide between Amy and Jill.

If the appositive word or phrase is essential for clarity purposes, omit the comma. For example:

The backstabbing slut known as Jill would soon get her comeuppance.

Commas are needed to set off items in a date. If the complete date is given, a comma is needed before and after the year. For example:

On August 30, 2012, the you-know-what hit the fan when Amy, Shaun, Brad, and Jill all attended the ill-fated high school reunion.

If only the month and year are given, don’t include a comma after the month.

August 2000 would prove to be an expensive month, given the upcoming divorce proceedings, physical assault charges, and other litigation expenses.