"I love Kateřina, while he hates her."
Translation:Já Kateřinu miluju, kdežto on ji nenávidí.
I left out "Já" since that is implied anyway by miluju. Why is that wrong?
Here you are making a contrast between I and He so it would be strange to leave it implicit.
One more thing... Is there a reason there are no "tips and notes" for this chapter?