YOU SAID:

as that alone would cause him to lose sleep at night.

INTO JAPANESE

それだけで夜に彼は眠りを失うからです。

BACK INTO ENGLISH

That's just because he loses sleep at night.

INTO JAPANESE

それは、彼が夜眠れないからです。

BACK INTO ENGLISH

Because he can't sleep at night.

INTO JAPANESE

彼は夜眠れないからです

BACK INTO ENGLISH

Because he can't sleep at night

INTO JAPANESE

彼は夜眠れないから

BACK INTO ENGLISH

Because he can't sleep at night