Part 1 of Essay
Many writers think it is a good idea to sprinkle commas every few places in there writing, but this makes for difficult reading. Here are some places commas should not be used: * After and, but, and or, unless the comma sets off a dependent clause (a phrase which can't stand alone as a sentence). Examples: Wrong- B ....

Part 2 of Essay
.... leaving them out, as in “ the first, second and third chapters,” is a habit picked up from journalism. Though it saves a little space and effort, omitting the final comma suggests the second and third chapters are some sort of special pair. ....