"Why are you going?"
Translation:Mengapa kamu pergi?
In Indonesian, the noun is always followed by the verb (especially if it's the root word). So instead of "Mengapa (why) pergi (go) kamu (you)", the correct answer is "Mengapa kamu pergi?". "Kamu" (you) is the noun and "Pergi" (go/leave) is the verb, that's why "mengapa pergi kamu" is incorrect.