YOU SAID:

He had no idea what was waiting for him.

INTO JAPANESE

彼は、彼を待っていたものは考えていた。

BACK INTO ENGLISH

He was thinking what was waiting for him.

INTO JAPANESE

彼を待っていた彼は考えていた。

BACK INTO ENGLISH

Thought he was waiting for him.

INTO JAPANESE

彼は彼のために待っていたと思った。

BACK INTO ENGLISH

I thought he had waited for him.

INTO JAPANESE

私は彼が彼を待っていたと思った。

BACK INTO ENGLISH

I thought I had him waiting for him.

INTO JAPANESE

私は彼を待っている彼を持っていたと思った。

BACK INTO ENGLISH

I thought I had him waiting for him.