A couple years ago for Christmas I bought my mom the hardback copy of the 16th edition Chicago Manual of Style, and she loved it.
I didn’t grow up to be an editor because my mom is an editor. Well, maybe I did. But that’s not the point. The point is that we (as well as most of the rest of our family) have a love of grammar in common and we often spend a lot of time commiserating over many people’s incorrect use of it.
The other day my mom was complaining about one of her client’s (let’s call him “my brother”) unnecessary addition of commas. I hate unnecessary commas as much as the next person, but in this case, I informed my mother, my brother was correct and the commas should have remained. She was certain that she was right, but I explained the rule and advised her to look it up in the handy manual I bought her.
I then decided it was best to review her understanding of that vs. which, and found that she was wrong on that as well. She assured me that the rule she stated was correct–at least, it had been many years ago when she started editing. And that probably was the rule then. But unfortunately, language is mutable, and therefore so are its rules.
This experience with my mom was a good reminder to me that it’s important to stay current with grammar rules. That’s why I’m taking some time to look over the old editing books that I have as well as checking out some new ones. As I go through them, I’ll attempt to share some of their nuggets of wisdom with you.
In the meantime, here’s the rules I reviewed with my mom.
- Commas in restrictive and nonrestrictive appositives. CMOS states, “A word, abbreviation, phrase, or clause that is in apposition to a noun (i.e., provides an explanatory equivalent) is normally set off by commas if it is nonrestrictive—that is, if it can be omitted without obscuring the identity of the noun to which it refers.” It continues, “If, however, the word or phrase is restrictive—that is, provides essential information about the noun (or nouns) to which it refers—no commas should appear.”
- Example of the first: Ursula’s husband, Jan, is also a writer. (Ursula has only one husband.)
- Example of the second: O’Neill’s play The Hairy Ape was being revived. (O’Neill wrote a number of plays.)
- “Which” vs. “That”. CMOS’s explanation is lengthy, so I’ll just say that if the information is integral to the sentence and leaving it out changes the meaning of the sentence, use “that.” If it’s unnecessary, superfluous, or in any way extra, use “which.” “Which” requires a comma. “That” does not.
- Example of that: The version of the manuscript that the editors submitted to the publisher was well formatted.
- Example of which: The final manuscript, which was well formatted, was submitted to the publisher on time.