I imagine a dog’s life as simple, easy-going, and uncomplicated. In writing these five-minute tips, I strive to keep my explanations the same, using a few simple examples not requiring the reader to look up grammatical terms. Not to say I don’t study grammar books, but I strive to weed out all the unnecessary stuff.
In The Everyday English Handbook, Leonard J. Rosen gives an informative explanation of when to use “that” and when to use “which,” by defining relative clauses, then further defining essential and nonessential relative clauses. The explanation is little more than a page, but it was more than I asked for. The Elements of Style explains when to use “that” and “which” by defining them as restrictive pronouns or nonrestrictive pronouns. Great information from both books, but it’s been a while since my last English class and the terms essential relative clause, nonessential relative clause, defining pronoun, non-defining pronoun, restrictive pronoun, nonrestrictive pronoun, make me throw up my hands.
Since this is a five-minute writing lesson, I want to keep it dog-simple. When in doubt, always use “that” unless it makes the meaning ambiguous. If a pause is necessary, it probably requires a comma, so use “which.”
Here are a few examples:
“The liver-flavored biscuit that is my favorite treat is buried in the backyard.” This means he has other biscuits hidden elsewhere, but he’s thinking about the one in the backyard. No comma is needed before “that.”
“The biscuit, which is liver-flavored is buried in the backyard.” His favorite biscuit is liver-flavored, not beef or chicken-flavored. A clear indication of “which” being the correct word is the need for a comma before it in the sentence.
“The smell of bacon that had been frying in the pan made me forget about my buried biscuit.” This means the bacon frying in the pan, not the uncooked bacon on the counter. Again, no comma preceding.
“The smell of bacon, which had been frying in the pan, made me forget about my buried biscuit.” Only this particular bacon is what caused the dog to forget the biscuit. Again, no preceding comma.
A dog can’t read or write, but he knows what’s what, and what he’s not sure of isn’t important.