the teacher u hate..

i definitely hate Umbridge. She isn't even a proper teacher in the first place("turn to chapter xxx and read. There will be no need to talk.")(thinking that Defence against the Dark Arts can be learned দ্বারা just reading,never practising). The only reason she got sent to hogwarts was to be the ministry's spy.she's also downright irritating with her fake sugar sweet voice.Hypocritical too.

Umbridge. Like the পূর্ববর্তি post pointed out, she wasn't really a teacher. অর্থহীন planted her there to corrupt the school.

Likewise, the Carrows. We don't see them teaching, but the glimpse from the DA's descriptions in enough.

And lastly (I know I'm going to get hated for this) Snape. He's a good character, and a good spy. But a poor teacher. He lets his prejudice towards some of the students interfere in how he treats them and teaches them. He completely failed in teaching Harry Occlumency.

Trelawney is actually ok, as a teacher. Its her subject which is flawed. Divination seems to be a skill someone either has অথবা doesn't have. And her predictions about Harry were initially confusing Sirius' dog form with a Grim, and later I think she kept foreseeing the forest scene.

Umbridge, and Fake-Moody.