YOU SAID:
I swear to not eat the whole mayonnaise again.
INTO JAPANESE
私は二度とマヨネーズ全体を食べないことを誓います。
BACK INTO ENGLISH
I swear I will never eat the whole mayonnaise again.
INTO JAPANESE
私は二度とマヨネーズ全体を食べることはないと誓います。
BACK INTO ENGLISH
I swear I will never eat the whole mayonnaise again.
You've done this before, haven't you.