In addition to being bullied, he could also be acting out other emotional issues that further alienate him. Saying I hate you to a teacher sounds like built up anger.

I strongly believe kids with such problems need someone to 'take them under their wing' and believe in them. Particularly someone outside of the family. He is on the cusp of transitioning between a child and a young man. It's an especially crucial time to reach him.

I've seen this happen to young boys in the neighborhood where I used to live. They don't have fathers in their life and other potentially adverse situations. They act out. They get repeatedly punished by the school, which further alienates them, ostracizes them, ultimately destroying their self-esteem. Many schools are now criminalizing behaviors that were previously dealt with by in-house punishments; particularly older kids. If someone doesn't intervene, if nothing changes, he may end up with a criminal record. I've seen this happen to boys who the average person wouldn't think of as criminals.

Also what phaset said--that is very important.

I am really sorry for your grandkid. It's really sweet of you to care.