No punctuation mark seems to give people so much trouble as this little squiggle that dangles below a line of text (as opposed to an apostrophe, which some of my students have called “the comma in the air”). The comma just seems to stump folks, and for good reason. It really has only one job – to be the walls of a sentence that keeps parts separate from each other – but it seems to be the nails – the things that hold the house of sentences together.
So let me see if I can cover the basics of the comma. First, this is a comma – ,. Nothing snazzy, just a little elongated period. Secondly, a comma’s job is to separate things; it keeps the various portions of a sentence divided from each other so that a reader can make sense of them. Example – The comma is used in many different ways, but it only has one purpose. The comma before but here separates the first part of the sentence from the second part; therefore a reader knows that those parts are linked in meaning but separate in structure. Make sense?
So here is a list of the most common places to include a comma. You’ll recognize most of them.
1. In a list. The internet gives me information, connects me with people, and helps me waste huge amounts of time.
2. After introductory material. After finishing her blog post, Andi will probably spend a bit of time on Facebook reading about the children of people she no longer knows.
3. In a compound sentence (i.e. a sentence that contains two complete, smaller sentences). Sites like Facebook and Twitter really entertain me, but they can also make a little obsessive about what’s happening.
4. Between adjectives. The fast-paced, manic style of Twitter appeals to me only when I am already in that state myself.
5. Around nonessential/nonrestrictive phrases (i.e. phrases that are not required for the meaning of the sentence). My blog, which has been running for over two years now, discusses books, writing, teaching, and grammar.
6. In dates, addresses, place names, and long numbers. According to Internet World Stats, 360,985,492 people used the internet in 2009.
7. With quotations. My father says, “He hates the internet,” and then he uses it all the time.
The key is to remember that you only want to use a comma when you want to indicate a separation between two parts of a sentence. Don’t drop it in every time you pause (That’s a favorite short cut that many English teachers use, and it often results in really scary sentences.). Just use it the ways described above, and you will be a comma master. (No light saber comes with this title, but you will get lots of smiles from teachers and bosses.)
Hope this helps. Feel free to ask questions of clarification if you’d like, and since this grammar/style/syntax/etc. topic will be the Friday choice for the future, please post your questions or topics for future discussions. I’m happy to help.