I don't know all the specific rules of grammar and punctuation but I can make myself understood, hopefully well, in written and verbal communication. The whole point of communication is to allow someone to understand you. If you're misunderstood, or not understood at all, the most logical place to start would be with your own communication. Sometimes the recipient is at fault, but often it's the communicator who fails to adequately communicate.
Today the major Sacramento newspaper ran an article entitled It's Hip To Be Grammatically Correct, and my heart soared. Two books about grammar were mentioned in the article--and I've read them both. Recently. Personally, I thought Eats, Shoots and Leaves was, how shall I put it nicely, not so good, but Woe Is I was extremely well-written.
I don't follow all the punctuation rules we're taught in school but I am consistent with what I do. From one of the books mentioned above I learned that some of what I do is actually considered English punctuation as opposed to American punctuation. Just as an example, if I put something in quotation marks and a punctuation mark goes at the end, I only put the punctuation mark inside the quotes if it ends the statement within the quotes--otherwise, outside it goes. Here's what I mean:
God sent a message to Pharoah, "Let my people go." The period ends the statement in the quotation marks, so that's where I put it. The period serves double duty, ending both the statement in the quotation marks as well as the entire sentence. Then there's this sentence:
The President referred to three countries as an "Axis of Evil". What's inside the quotation marks doesn't need a punctuation mark, so I place it outside to end the sentence. Apparently this is an English way of doing things.
One change in punctuation that I've never understood is the serial comma. I was taught to put a comma after each item in a list, including the item before the "and". Example: The colors on the American flag are red, white, and blue. Some new usage drops the last comma, giving: The colors on the American flag are red, white and blue. That doesn't look or sound right to me--it seems like the white and blue are grouped together, somehow, like peanut butter and jelly. I'll now give two examples of the same sentence, punctuated the old-fashioned way (which I prefer) and the more modern way.
My favorite sandwiches are roast beef, turkey, peanut butter and jelly, and bologna. (old style)
My favorite sandwiches are roast beef, turkey, peanut butter and jelly and bologna. (new style, omitting the comma before and)
It's very clear when using the old rule that I have four favorite sandwiches. It's also crystal clear what those sandwiches are. The new method makes it look like I have only three favorite sandwiches, and the last one is pretty yucky.
I also know how to use a semicolon effectively; unfortunately, so few do. =)
I've also noticed, perhaps in the last decade or so, people who speak in a way that they think makes them sound educated but actually makes them come across as pretentious idiots. "We should conversate about this before making a decision." The word is converse, dude. "Bring the report to myself when you're done with it." When did substituting myself for me even sound good, much less intelligent?
There's also street language that's made its way into common usage. Use of the prefix dis- to mean disrespect--what's up with that? When did disrespect become a verb instead of a noun? Why doesn't the new word dis mean disconnect, disagreement, disembarkation, dishonorable, dissatisfaction, or distinguished? We all know the answer, it just wouldn't be politically correct for me to state it here.
I find the topic exceedingly interesting but I'm not going to write any books about it. This post will be about as far as I go. Still, people who make the most basic mistakes on a regular basis come across to me as uneducated. And since all of us adults (not we adults) had the opportunity to get at least 12 years of education, I'd like to think we could write and speak at least passably well.