YOU SAID:

Once upon a time, there was an engineer.

INTO JAPANESE

かつてエンジニアがいました。

BACK INTO ENGLISH

There used to be an engineer.

INTO JAPANESE

以前はエンジニアだった。

BACK INTO ENGLISH

I was an engineer before.

INTO JAPANESE

以前はエンジニアだった

BACK INTO ENGLISH

I was an engineer before.