How do you know that Severus snape is good?

Answer 1

I do not think so as he wanted to harm Harry Potter all the time and he subtracted a lot of points from harry potter's house and supported Draco Malfoy and Slytherin the most.

Plus, he made Neville's life a misery just for fun.

Answer 2

Snape turned good around the time Harry was born. That was because he found out that Voldemort was hunting Harry's family down and would kill them all. He had loved Harry's mother, Lily Evans, from when they were children. So, he asked Dumbledore to protect them, and in return, he became good and became a spy.

Answer 3

Snape gives Harry his memories as he is dying of he and Harrys mom and he and dumbledore speaking about Harry. The whole time Harry thought tht snape was working for voldemort, he really was, but he was only pretending, he was really dumbledores all along. No one knew.Harry found out from snape memories he looked at through the pensive.