YOU SAID:
When did you have lunch?
INTO JAPANESE
いつお昼ご飯を食べましたか?
BACK INTO ENGLISH
When did you eat lunch?
INTO JAPANESE
いつお昼を食べましたか?
BACK INTO ENGLISH
When did you have lunch?
INTO JAPANESE
いつお昼ご飯を食べましたか?
BACK INTO ENGLISH
When did you eat lunch?
INTO JAPANESE
いつお昼を食べましたか?
BACK INTO ENGLISH
When did you have lunch?
it is unlikely that this phrase will ever reach equilibrium