A Little-Known Dash Rule

Besides using the dash for interruptions (broken sentence structure), there are some grammar rules that govern the use of the dash.

When a pronoun refers back to one noun, use a comma in front of the pronoun; when a pronoun refers back to several nouns, use a dash in front of the pronoun.

…We received several letters, each of which I answered.
…We received letters, cards, and emails — each of which I answered.

…I sent it to three friends, all of whom I expected to attend.
…I sent it to Ray, Anita, and Roxanne — all of whom I expected to attend.

Happy punctuating!

Margie