I’ve been thinking about this because we’re doing the final copyediting for our book . . . there are some words you just can’t use because people get confused:
– “which” and “that”: Some people, including copy editors, are confused on this; see here for more on the topic). The short answer is that you can use “which” pretty much whenever you want, but various misinformed people will tell you otherwise.
– “comprise”: I once had a coauthor correct my manuscript by crossing out “comprise” and replacing with the (wrong) “is comprised of.” I try to avoid the word now so that people won’t think I’m making a mistake when I use “comprise” correctly.
– “inflammable”: This one has never come up in my books, but I’ve always been amused that “inflammable” means “can catch fire.” But it sounds like it means “nonflammable,” so now we just use “flammable” to avoid confusion.
– “forte”: According to the dictionary, it’s actually pronounced “fort,”, not “fortay.” But everybody says “fortay,” so I can either use it wrong, like everybody else, or say “fort” and leave everybody confused. I just avoid it.
– “bimonthly”: I think by now you know where I’m heading on this one. Again, I just avoid the word (on the rare occasions that it would arise).
– “whom”: I never know whether I should just use “who” and sound less pedantic.
– splitting infinitives: I do this when it sounds right, even when (misinformed) people try to stop me.
By the way, my copy editor has been great. He’s made lots of unncessary comments (for example, on “which” and “that”) but I just ignore these. More importantly, he’s found some typos that I hadn’t caugh.