It would be remiss of me to approach so near National Grammar Day without bringing up punctuation. Punctuation sometimes seems like the appendix of the body of grammar, because oftentimes you can eliminate it entirely and still make something worth reading (I'm looking at you, James Joyce). But in reality it's probably something more like the spleen or gallbladder: you can get by okay without it, but things tend to run more smoothly with it in place.
I think what I like so much about this sentence from the Practical is its sheer hypocrisy: look how many parentheses are there!
The other fun thing about punctuation is that it has drastically, visibly changed over the language's evolution. For instance, Jane Austen's most famous sentence: It is a truth universally acknowledged, that a single man in possession of a good fortune must be in want of a wife. Note that comma after acknowledged -- nowadays we would leave that sucker out in the cold to die. But Jane Austen thought there should be a pause there, and so in the comma went, to signal a breath in the middle of what is otherwise a bit of a mini-marathon: It is a truth universally acknowledged that a single man in possession of a good fortune must be in want of a wife.
Butler is having none of this:Jane of course was writing at the beginning of the nineteenth century, and Butler at the end of it. This century saw sweeping changes in not only the literacy rates but in the way reading was approached. Austen's time was still very rooted in oral culture. Letters were important, but were often read aloud to the family as a whole, and conversation was considered an art that required training and rules and delicacy. By the end of the century, however, writing (in the form of newspapers, magazines, and so on) had become the unquestionably central cultural medium. Butler, in his grouchy Victorianism, considers the rules of grammar and syntax a greater good than the actual behavior of words in a human mouth.
And, to fully illustrate the gap between language written and language spoken, here is Victor Borge's Phonetic Punctuation: