YOU SAID:

i hate my sister so i killed her

INTO JAPANESE

私は私の妹を憎むので、私は彼女を殺した

BACK INTO ENGLISH

I killed her because I hate my sister

INTO JAPANESE

私が彼女を殺したのは、妹が憎むからだ

BACK INTO ENGLISH

I killed her because my sister hates her.

INTO JAPANESE

私が彼女を殺したのは、妹が彼女を憎んでいるからだ。

BACK INTO ENGLISH

I killed her because my sister hates her.