Good news first. The course on grammar basics that I recently signed up for (internal link) is very well done. I think completing its 16 sections will give me a solid background for taking the U.C. Berkeley extension course (internal link) in September. Now for the bad news: grammar is hard!
Consider these two sentences from The Elements of Grammar by Margaret Shertzer. “A relative pronoun introduces a subordinate clause that modifies a noun or a pronoun occurring earlier in the sentence and connects a dependent clause to the main clause. It is also a substitute word that refers to its antecedent and stands for that antecedent in a subordinate clause.” Sheesh!
To understand what a relative pronoun is we would first have to know what five other words or phrases means: subordinate clause, pronoun, dependent clause, main clause, and antecedent. And what it means to modify a noun. This will be slow going, I don’t know what the expression is for “learning everything at once.” But that feels like what I will have to do.
Fun fact! What does a noun describe? Yes, a person, place or thing. But also an animal and an idea. To reduce the question to its simplest terms, The Chicago Manual of Style puts it like this. “A noun is a word that names something, whether abstract (intangible) or concrete (tangible).” See? I’m learning.
July 16, 2015 Update. Another book says activities are nouns. Like the word “orbiting.” Does that mean circling or turning are nouns? I cannot think of a sentence in which the word “orbiting” could be used as a noun. Or is this a possible sentence? “Orbiting is an activity.”