Even though I am barely qualified, I have found myself teaching Middle School English. In order for the students to have a better understanding of clauses, I have insisted that they punctuate compound sentences with a comma and a coordinating conjunction, instead of just the conjunction. The students in their creative and essay writing have not demonstrated that they can distinguish an independent clause from a dependent clause. I know that in the long run this rule is optional, and certainly much of what we read omits that comma. Perhaps, though, the rule is optional for writers who can identify clauses in sentences. What do you think?
Well, you asked for an OPINION, so here's mine:

I have an unorthodox view on punctuation. I don't really regard it as part of grammar proper. Like spelling, punctuation is an artifact of writing, of WRITTEN language. Grammar existed long before writing existed. Puncuation did not. I therefore take the view that if you can't HEAR the difference when the sentence is spoken, then the difference is artificial.

...but that's not a commonly held point of view, so feel free to ignore me. (Especially if you're an English teacher).

But sometimes with or without a comma makes slight difference in the meaning of a sentence.

eg. Peter who has just graduated from the University is his son. ( He has a few sons, peter is one of them )

eg. Peter, who has just graduated from the University, is his son. ( He has only 1 son named ' peter )Emotion: smile
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I think you are exactly right (the rule is optional for writers who can identify clauses in sentences - i.e., artistic license). My rule for middle-school kids would be: you must use the comma in compound sentences until you have fully proven your skills as a writer.

Some years later, when they write well enough to argue intelligently about the finer points of commas, then they've earned the right to use them as they please!
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