YOU SAID:
He was waiting for the rain to stop
INTO JAPANESE
彼は雨が止むを待っていた
BACK INTO ENGLISH
It stops raining he waited
INTO JAPANESE
彼は待っていた雨が止む
BACK INTO ENGLISH
He was waiting for it stops raining
INTO JAPANESE
彼は雨が止むを待っていた
BACK INTO ENGLISH
It stops raining he waited
INTO JAPANESE
彼は待っていた雨が止む
BACK INTO ENGLISH
He was waiting for it stops raining
it is unlikely that this phrase will ever reach equilibrium