Punctuation

Q. I am a little confused about how to properly use an em dash in the case of independent clauses. I thought that it should not be used to join two independent clauses, but I see it used this way all the time, and there is nothing definitive about its use in this instance in your book. Here’s an example: This plan isn’t like other diets—in fact, it’s not a diet at all. Please help me settle this issue once and for all!

A. There is no rule against joining two independent clauses with an em dash, as the examples at 6.82–87 illustrate. The em dash may be used in almost any syntax where a break is needed.