"Whu?" would be the literal translation, and would incorperate the feelings/ideas of "Where am I? Wait. Why is there a person there? Kill? No, friend. Why there? What did I do last night? Danger, LARP, party? How did he get to my house...er...or me to his? Am I naked (how I often sleep)? Check for pulse" The thoughts would vary a bit, depending on the answers to where I was (LARP vs house) and what I'd been doing (did you hop into my cabin to flee the Evil Whatever, or do I have No Clue how you came to be there). But that's roughly how my thoughts would go.
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'Whu?' as a paragraph
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Re: 'Whu?' as a paragraph