Disclaimer: I'm not getting this from a rulebook. This is just about what makes me cringe.

- "Where froze over?" (bad)

+ "What place froze over?" or even "What froze over?" (good)

+ "You went where?" (good, if emphasized)

+ "Where did you go?" (good, official version)

- "When works for you?" (bad)

+ "What time works for you?" (good)

Question form vs. "Let me know ..." "I wonder ...":

"What time works for you?" ("Let me know what time works for you.")

"When do you want to X?" ("Let me know when you want to X.")

"When can we X?" ("Let me know when we can X.")

"When are you available for X?" ("Let me know when you are available for X.")

"Do you X?" ("Let me know if you X.")

"Where did you come from?" (Let me know where you came from.")

etc.