Commas can be confusing and intimidating.There are so many rules and they can seem quite subjective. I chose four to review here. I review these with my students all the time!
Items in a Series: Use a comma to separate three or more items in a series.
Please sharpen your pencils, take out your textbook, and start working on your essays.
I am having eggs, milk, and pancakes for breakfast.
Use a comma before a coordinating conjunction to join two independent phrases (an independent phrase is a phrase that could stand alone as a complete sentence.)
We are going to the mountains on vacation, but we are only staying three days.
Use a comma to separate cities and states. Use a comma after the state's name if it doesn't end the sentence (my students always forget the comma after the state.)
My grandmother lives in Denver, Colorado.
Atlanta, Georgia, is my destination.
Use commas between adjectives where “and" could be used. In other words, use a comma if you can insert the word “and" between the two adjectives. Do not use a comma if the word “and" can’t be inserted.
My Algebra teacher’s challenging, extensive exam thoroughly covered Chapter 11. (You use a comma because if you wanted, you could say, “My Algebra teacher’s challenging and extensive exam thoroughly covered Chapter 11.")
My parents live in a small brick house. (You would not use a comma here because you would not say, “My parents live in a small and brick house."Obviously, that does not work!)