The practice of diagramming sentences first began in America in the middle of the nineteenth century. Set against the full history of grammatical study, diagramming is a relative newcomer. Language has been studied systematically since at least the second century
bce in the western world, and even earlier in India. Yet sentence diagrams—visual depictions of the relationships among words—were developed only after over 2000 years of study. From our vantage, the desire to visualize sentence structure may seem like an intuitively obvious move.
When I taught linguistics-for-teachers courses, I spent a significant portion of my class time trying to get students to question their assumptions about language, assumptions that, whether they learned them in school or by general osmosis, are based on premises that linguists know to be incorrect. It always distressed me, therefore, when certain students would make it to the end of the course and drop some comment that made it clear they had internalized little of what I was trying to communicate.
Almost everyone was taught in school to avoid using the passive voice. Fewer know how to identify the passive voice, but I'm going to assume for the moment that you are part of the elite who can and ask you to do a little grammatical analysis with me.
Sally Thomason has been championing a kind of humane prescriptivism, which is surely a bit unusual for the crew at Language Log, but I have a great deal of sympathy.
In the context of language-arts education, a certain prescriptivism is unavoidable. There is a written standard, like it or not, and there are social consequences to violating the standard in certain contexts.
Grammar teachers (and I mean those who are actually teaching grammar, not grammar-school teachers) could pick up a few pointers from math teachers. Thanks to a recent post on The Quick and the Ed, I learned about a great book by Liping Ma on teaching elementary mathematics. I've just ordered the book from Amazon, so all I've had a chance to read is the snippet available on the search-inside pages, but I immediately ran across some very interesting remarks that seem directly relevant to grammar pedagogy.
This Washington Post article is a little different from your run-of-the-mill story on how the new Writing section of the SAT has affected education in that it focuses on the multiple-choice part, and the way that those questions have been encouraging a return to explicit grammatical instruction.
The distinction between proper and common nouns is probably familiar to you from your earlier education. Fred and Netherlands are instances of proper nouns. A proper noun is a type of noun that refers to a specific person, place, or thing (Evelyn, Cairo, Saturday, etc.) Common nouns refer to classes of things (cat, trash, stone, etc.) rather than particular ones. All nouns that are not proper are common.
High-stakes tests come in for a lot of criticism in various quarters, not all of which is particularly well informed. One of the primary downsides, as far as I'm concerned, particularly given the way many of these tests are administered, is the corrosive effect that they can have on teachers and administrators.