YOU SAID:
What are we having for lunch?
INTO JAPANESE
昼食に何を食べようか。
BACK INTO ENGLISH
What to eat for lunch?
INTO JAPANESE
お昼に食べる?
BACK INTO ENGLISH
You eat lunch?
INTO JAPANESE
お昼を食べましたか
BACK INTO ENGLISH
You eat lunch?
That didn't even make that much sense in English.