YOU SAID:
I solemnly swear I am up to no good.
INTO JAPANESE
私は厳粛に私はダメになっていると誓う。
BACK INTO ENGLISH
I solemnly swear I am no good.
INTO JAPANESE
私は厳粛に私はダメだと誓う。
BACK INTO ENGLISH
I solemnly swear I am no good.
You've done this before, haven't you.