^Really amazing advice from a parent! Kids really draw off of how their parents handle something (after all, aren't we supposed to act like adults?). Seeing your Dad yell and get into an argument with another parent or teacher over the treatment of a kid can lead to the kid also reacting aggressively the next time something like this comes up.
Now, from a someone younger, I hope I can give you my piece on it. Tragically enough, bullying in rampant nowadays. I was bullied when I was a little kid, and let me tell you, the saying "sticks and stones may break my bones but words will never hurt me" is a complete fallacy. Words hurt. Especially to a kid, when you're insecure about everything, still trying to figure out how this whole friendship thing works.
Kids say mean things, you say mean things back, and it just gets more and more horrible until one or both of them are crying and now it's just traumatic. The best piece of advice my parents ever gave me (not that I appreciated it at the time, but now I completely understand), is "Just be nice to people". Literally no one is mean to the nice kid who's friends with everyone. If they are, then the group as a whole regards them as a bully, and ostracizes them for it.
Why you picking on him? He told me he liked my Captain America shirt.
Why did you say that about her? She offered to be my reading partner.
Why are you being mean? Everybody likes him.
The reason words hurt so much is that they're usually over something the the kid is insecure about. Help them realize that it's ok if you have a lisp, it's ok if you're a little chubby, it's ok if your bad a soccer! Who cares?
You have lots of friends who like you for you! And those who are mean, well, you wouldn't want to be their friend anyways if that's how they treat people.
Saying these things might not be extremely effective now, but let me attest to the fact that they have helped me IMMENSELY later on in life, especially through the hell that is high school. I wasn't always the nice little kid, I was bitter about how I was treated so I responded in kind, lashing out, saying mean, hurtful things to make myself feel better. Don't let that happen to your grandkid. And now, I realize something about those kids who say rude things-most of them feel horrible. As you get older, you start to realize that there is literally no difference between us, we all feel the exact same thing.
So, comfort him, tell him that it's ok to feel hurt by these things, but make sure he knows the difference between some angry little kids opinion, and the fact that there are many more people who love him inside and out. Now, if someone says something rude, I laugh, because they must be very sad and bitter on the inside, while I have many friends who love my company, my smile, and me for me.
Hes going to grow up to be perfect, he has y'all to look out for him:)
I have run into bullies at the park several times with my daughter. She is 8 and has autism. I have zero problems yelling at other children when they step over the line and pick on my daughter. If your child can't defend themselves then you need to. If I see a parent or caregiver around I will approach them and explain that their child is picking on my child and I am not ok with that. If it escalated from there I would call the police if I needed to. Just stay calm and speak up. If your child sees you defending them and even turning the situation around he may feel more confident and less scared.