You don't have to be a mechanic to drive a vehicle.

With all due respect, Wordwind, it seems to me that there should be a class called "Common Sense Writing" which students have to take before they are introduced to the "rules" of punctuation and a whole lot of other "rules".

"Common Sense Writing" would teach students that the purpose of "rules" is not to frustrate and confuse them (as most students naturally assume), but to make it easier for the reader to understand what they are writing.

The first thing a teacher of "Common Sense Writing" would do is put an unpunctuated sentence or sentences on the blackboard which would benefit from the addition of punctuation.

Then that teacher would allow the students to discover for themselves, by speaking the sentence aloud, how that sentence becomes clearer and more understandable and more emphatic by inserting 'breaks', or 'pauses' or 'little breaths' in the sentence -- which eggheads call "punctuation".

Once the students get into the rhythm of it, tell them that there isn't anything else to master.

All this "introductory prepositional phrase" hogwash is just the mechanical stuff under the hood of the car. Who needs it if you just want to learn how to become a good driver?

Then students should be told that mechanics don't necessarily make better drivers than people who don't know a carburetor from a tailpipe. In fact, there is a danger that a mechanic will pay too much attention to what is going on under the hood and not enough attention to what is going on in the road ahead.

Contrary to the impression which the "rulebooks" give, the rules serve good writing, not the other way around.

Good writing is clear, understandable writing - in other words, "Common Sense Writing".