Tuesday, September 23, 2008

The Five Minute Comma Lesson

When it comes to proper comma usage, the advice out there can range from complete avoidance to complete saturation.

I once heard a professor of English say, "Commas are a complete mystery to me, so I just leave them out." At the other extreme, almost all of us have heard at least one time or another, "Every time you take a breath, put a comma there." If you do not want to avoid commas completely but also want to avoid complete comma saturation, here are a few guidelines that will help you decide where to put that confusing little squiggle.

1) Know Your Clauses

If the word "clause" scares you or only brings up images of Christmas, then you may first need to ask yourself how you know when a sentence is a sentence. Though there are always exceptions, a sentence is a group of words that contain a subject and a (conjugated) verb that together express a complete thought.
If your group of words fits this description, you have an independent clause. What, you may ask, is a "complete thought?" This is where your feeling or intuition plays a role; you just sense that it is.

If the group of words contains a subject and a verb but does not express a complete thought or cannot stand alone, you have a dependent clause. Dependent clauses often contain a dependent marker word, such as "because," "although," or "since."

If the group of words is missing a subject or a verb, it is considered a fragment.

2) Compound Sentences

You can use commas to separate clauses in a single sentence. If you want to combine two independent clauses, use a comma followed by one of seven conjunctions (and, but, or, for, nor, yet, so).

Example: I am going to the store, and my brother is cutting the grass.

Use a comma to separate dependent clauses that precede independent clauses. If dependent clauses follow independent clauses, commas are usually not required.

Example: Because my brother is cutting the grass, I am going to the store.

Generally speaking, you are only allowed a maximum of two independent clauses in one sentence. Exceptions can be made, but be wary of packing too much information into one sentence.

3) Series

Any series that contains three or more items should be separated by commas. There is some debate about whether to put a comma before the final item in the series. The general wisdom is to pick one method and use it consistently throughout the paper.

4) Non-essential Elements

Groups of words that are not essential to the meaning of the main clause should be set off by commas. These would include interjections, appositives (renaming a noun), and quotations.

5) Geographical Names and Dates

These are sometimes overlooked. Remember that a comma should separate cities from states, but they should also separate cities and states from countries.

Example: The Purdue Writing Lab is located in West Lafayette, IN, USA on the campus of Purdue University.

Commas should separate the day of the week from the date and month and the date and month from the year. They should NOT separate the date from the month.

Example: The conference begins on Friday, October 11, 2008.

6) Now It's Your Turn!

Add Your Simple Comma Guideline (not rule) to Our Five Minute Lesson


Anonymous said...

Good one, Brady!

Anindita Basu said...

Great post. Simple guidelines such as these definitely help us remember stuff!

My guideline? I always put a comma after words that "carry on the flow" - words such as Therefore, However, Consequently, ... I believe they're called conjunctive adverbs?

Anonymous said...

Once again, a super suggestion Anindita.

Did you vote on the 'that' poll, BTW?

Anindita Basu said...


I did, and I disagreed! Mainly because it said "any" sentence.

LoriA said...

This is a great lesson. There is one bit, though, that I think might need clarification:

#2 Example: I am going to the store, because my brother is cutting the grass.

When the subordinate (dependent) clause follows the independent clause in a sentence, I am pretty sure the rule is to NOT use a comma. If the dependent (subordinate) clause begins the sentence, then the comma is required.

Brady Spangenberg said...

Dear Loria,

Thanks for your comment, and that was an oversight on my part. I have reworked #2 to reflect the current comma guidelines.


Anonymous said...

Thanks. Very helpful. However, I would like some more examples.

Anonymous said...

very heljpful,especially the fragment section.

Unknown said...

Thank you so much for the information. I am currently undertaking Ph.D and I am a little confused with the correct use of puntuation. Thank you for this inofmraiton, and I would also like to know about when to use the double "" marks and the single ''marks. Where the full stop should be used. I would really appreciate if you could recommend me a detailed puntuation guide book. Thank you

Susanna Carter said...

Hi Hyejeong
There is no one good punctuation book that I can recommend as punctuation and grammar are inextricably linked, so I would use a good grammar book or grammar reference book. I like Michael Swann's: Practical English Usage 2005 edition. Look it up on
As for your question about double quotation marks, my advice would be to look at the referencing style you are required to use and follow that. At UniSA we use our own version of Harvard Referencing where only single inverted commas are required but that is not the case with other systems. When you write for publication they give you a style guide to follow, so there is no absolute prescription or advice on that one either. I hope this helps.

ahmad lowkom said...

it's amazing to learn,about the comma but still hard for me more pratice make perfect