Shmoop's favorite dogs are pugs, bulldogs, and basset hounds.
See that comma after bulldogs? That's called the Oxford comma, and it's one of the most passionately debated pieces of punctuation.
Don't believe us? Just try bringing up the Oxford comma in a room full of grammarians, and watch the red pens and grammar guides fly. So what is it?
The Oxford comma (also known as the serial comma) is the comma that comes before the words and or or at the end of a list. Technically, it's optional. Whether or not you want to include it all boils down to a style issue. You definitely need to use one if the sentence would be ambiguous otherwise, but most of the time, leaving it out doesn't change anything.
Personally, we're big fans. We're all about consistency, and we think the Oxford comma adds clarity to lists. Check it out:
Accepting his MVP award at the basketball team's banquet, Ernie thanked his parents, Michael Jordan and God.
No wonder Ernie was the most valuable player on the team! In this example, the absence of the Oxford comma makes it sound like Ernie's parents are Michael Jordan and God.
We're pretty sure that's not the reality of the situation. Put the Oxford comma in after Jordan, and then there's no possibility for misunderstanding; it's clear that Ernie's thanking three parties: his parents, Michael Jordan, and God.