...ok, actually it's more like a quiz about the correct use of various homophones - their/they're/there, etc - but the quiz-makers threw in questions about which/that and who/whom to make you feel like you're working for it. Although, gotta say, if someone asked me "Whom did you see that the bar last night?" I would give them the wedgie they so richly deserved.
It's nice to be able to win these kinds of quizzes - 100% bitches! - but correct grammar is only correct in the correct contexts. Given the protracted and serious fighting I've been involved in on facebook over the use of the Oxford comma, fighting grammar sure can generate some heat. Like, I know that the less/fewer thing is loosening, and that split infinitives and ending a sentence with a preposition are legit, but they still make me itch.
I apparently have no problem with using "like" to open a sentence, or using "they" as the singular general pronoun, so, as usual, my grammar sensitivities are arbitrary and personal. I am never going to be okay with irregardless or a whole nother though, and you can't make me.