Can I tell my nephew if he hurts my daughter again that he'll be arrested?
What happened to make you threaten him?
A week ago he wanted a toy from my daughter and she refused to let him have it so he hit her.
Oh wow, your nephew needs to learn to behave better. It's only natural to want to protect your child and you're going about it the right way with your nephew. Hopefully he takes the threat seriously.
Yeah I think my nephew got the message and won't hurt my daughter again.
That's good, and it is always good to make sure that people know the limits at which they're allowed to go. You're setting a good example for both your nephew and daughter with this and I'm proud of you.