One of these years I should actually look up comma usage in American English.

[conuly]

I feel certain that we didn't actually cover this in school in any detail, but orthography really does have to be taught and I strongly suspect my natural instinct is to use commas a bit too much. I end up going back later and editing half of them out again.

Comments

[larryhammer]

Short answer: it's highly variable. While there are trends in comma usage in the large regional versions of English, none of them have set rules for all the cases. It's largely style and clarity rules, rather than dialect/grammar.

[cimorene]

Yeah, I'm afraid the only places that have hard and fast rules are stylebooks and the occasional magazine. Of course that doesn't mean that there are no absolutely wrong or right uses according to standard American written English, but it does mean that a lot of instances are debatable.

[redbird]

If/when you do, check how old your sources are: 19th century style was to use a lot more commas than late 20th century style.

[low_delta]

I didn't learn about comma usage in high school English, or whatever learning I did later on. This led me to believe there aren't any hard and fast rules. But then there was that one guy who had to tell me my usage was wrong. I was like, wtf? But he was an English teacher so... I guess there are actually rules?

And yes, I tend to go back and edit them out.