Everyone thinks comma rules are confusing, but they are not. In fact, there are only four general situations which warrant a comma! These general rules are
1) To join two sentences (in conjunction with a conjunction)
2) To add something to the FRONT of a sentence
3) To interrupt a sentence (in this case, you need two!)
4) In certain standard situations
While there are more specific rules under each general rule, this one page handout simplifies the comma rules and helps identify situations when using a comma is justified.
This is an ideal reference for any student or professional because it helps the person "justify" the comma. So often I will ask a student why he or she used a particular comma, and the answers I get are generally along the lines of "Just because," "I don't know," or "It was a long sentence." Now my students have learned to point to the "one pager" and identify the rule and sub-rule because they know they can't use a comma without justifying it.
I often use this prezi
as a way to introduce the concept and provide a mini-lesson. I usually copy the "one pager" onto a pink sheet of paper, and I usually give comma quizzes that I let them retake until they get at least an 80 or above.
This lesson is fun because I talk about how the poor comma is useful and good but that it must be exhausting to have to justify its very existence every single time it winds up in a sentence!
I also have the attached cartoon on a poster that has the words "Justify the Comma!" prominently displayed.
One last note - I'm not sure why the PDF downloaded as two pages. The second "one pager" is just a duplicate of the second.