YOU SAID:

I know it was that tiger who stole my watch.

INTO JAPANESE

私はそれが私の時計を盗んだ虎だと分かっています。

BACK INTO ENGLISH

I know that it is a tiger that stole my watch.

INTO JAPANESE

私はそれが私の時計を盗んだ虎であることを知っています。

BACK INTO ENGLISH

I know that it is a tiger that stole my watch.