YOU SAID:

When i was a young boy the dogs and cats were playing.

INTO JAPANESE

私が幼い頃、犬と猫が遊んでいました。

BACK INTO ENGLISH

When I was little, dogs and cats were playing.

INTO JAPANESE

私が小さい頃、犬と猫が遊んでいました。

BACK INTO ENGLISH

When I was little, dogs and cats were playing.