I’d saved this post from earlier and have just checked in. Harnby has a wonderful way of explaining clearly, with good examples. Not only did she note a problem I see often (U.S. writers thinking that “distanced” words should be in single quotes), but she also told me something I didn’t know, and I’m a grammar geek: that U.K. editing places quote marks inside the punctuation in nested quotes. I’d seen that practice but hadn’t made the leap to generalizing to the rule. Use this guide whenever you wonder what to do with those annoying ” and ‘ marks.