Today, my host mother told me that Koreans don't really ever say "오늘 어땠어요?" to ask the English equivalent, "How was your day?" While it's not grammatically incorrect, she said, it's just not normal.
I thought, "Oh dang, really? I've been saying that to you almost every day for the past six months!"
Instead of voicing that, though, I asked, "Well, then what do Koreans say instead? What question should I ask?"
As it turns out... there's no question. Just a cheerful "잘 다녀오셨습니까! (Welcome home!)" will do.
P.S. Pronunciation guide: 오늘 어땠어요 = oneul eot-daesseoyo; 잘 다녀오셨어요 = chal danyeo-oshyeosseoyo, where "eo" is /ʌ/ in IPA: kind of halfway between the English "uh" and "aw".