what you up to 點解 ?

What you up to 是鬼佬在Informal 情況下的講法，正確是What are you up to
意思是What are you going to do / What is your plan 。一般鬼佬　會講　What are you up to today 意即 今日有乜搞（今日做ｄ乜）　What are you going to do today / What is your plan today.
回答時example: (Peter) what are you up to today, (Mary) I am going to the movie tonight.

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