Over the years, I’ve tried to pick up most grammar rules (who vs. whom, further vs. farther), but the other day, I heard a basic grammar rule that was new to me…

Over the years, I’ve tried to pick up most grammar rules (who vs. whom, further vs. farther), but the other day, I heard a basic grammar rule that was new to me…

What’s the difference between which and what?

For example, if you’re looking at a dessert menu, would you ask your friend:
a) “What dessert are you going to order?”
b) “Which dessert are you going to order?”

The correct answer is…

Which!

Here’s the rule:

* You use “which” when there are a limited number of things to choose from. (“Which of her brothers is the cutest?” “Which seat did you choose in the car?” “Which pizza toppings will you pick from this list?”)
* You use “what” when there are an unknown (or very large) number of things to choose from. (“What country is he from?” “What is your favorite book?” “What kind of cake would you like for your birthday?”)

I fully realize this is the nerdiest post on Cup of Jo to date, but you guys seem to love grammar, so I’m going for it!!!

So: Did you know it? Do you have any grammar pet peeves?

P.S. Good grammar is sexy.