YOU SAID:

chins never undulate, unless the jaw is broken

INTO JAPANESE

あごが壊れていない限り、あごは決して起伏しない

BACK INTO ENGLISH

The chin never undulats unless it is broken.

INTO JAPANESE

あごは壊れない限り起伏ることはありません。

BACK INTO ENGLISH

The chin will not undulation unless it breaks.

INTO JAPANESE

あごは壊れない限りうごは起こりません。

BACK INTO ENGLISH

The jaw will not happen unless it breaks.

INTO JAPANESE

顎は壊れなければ起こりません。

BACK INTO ENGLISH

Jaws do not happen unless they break.

INTO JAPANESE

彼らが壊れない限り、顎は起こりません。

BACK INTO ENGLISH

Jaws do not happen unless they break.