what did you eat?
what have you eaten?
what are you eating?
what did you eat this morning?
What did you eat? or What have you eaten?
Have you eaten?
你有什么吗 经常说have you done
正确的说法应该是:What did you have?
what have you eaten? What did you have yet? have 可以表达吃的意思 What did you have for your super/lunch/breakfast?