YOU SAID:

I was seven before I was potty-trained.

INTO JAPANESE

トイレトレーニングを受ける前は7歳でした。

BACK INTO ENGLISH

I was 7 years old before potty training.

INTO JAPANESE

私はトイレトレーニングの前に7歳でした。

BACK INTO ENGLISH

I was 7 years old before potty training.