YOU SAID:

in my defence, i was left unsupervised

INTO JAPANESE

私の防衛で私は残っていた教師

BACK INTO ENGLISH

In my defense I teacher had left.

INTO JAPANESE

私の防衛で私先生が残っていた。

BACK INTO ENGLISH

In my defense I had left my teacher.

INTO JAPANESE

私の防衛で私は先生を去った。

BACK INTO ENGLISH

In my defense I left the teacher.

INTO JAPANESE

私の防衛で私は先生を残しました。

BACK INTO ENGLISH

In my defense I left the teacher.