Possible Duplicate:
Should I put a comma before the last item in a list?
Sometimes, I see an extra comma before an "and" but I don't know when I should and should not add a comma before an "and". For example:
There are apples, oranges and pears in the basket.
In this sentence, I don't think that there is no need for a comma before the "and pears". But sometimes, I see sentences having commas before "and". For example:
I have eaten my dinner, and I am ready go out.
In this case, is the comma before the "and" necessary? In longer sentences, I often see a mixture of with and without comma before "and". In what scenario should I then add a comma before the "and" in a sentence?
