YOU SAID:
I did not eat a hamburger today
INTO JAPANESE
今日はハンバーガーを食べませんでした
BACK INTO ENGLISH
I didn't eat a hamburger today.
INTO JAPANESE
今日はハンバーガーを食べませんでした。
BACK INTO ENGLISH
I didn't eat a hamburger today.
You've done this before, haven't you.