Depended on the situation. If I was bugging them then their reaction is justified. If it's just from an attitude then the consequence would be taking an item they love away for a bit

Firmly explain that sort of behavior is completely unacceptable, reestablish the expectation that we do not speak to each other that way and that being respectful is a rule we all follow, Setanta appropriate consequence like temporary removal from shared living spaces (being required to remain in one's room for a set duration).

Afterward, request an apology and set an expectation for an escalated consequence if the behavior is repeated.

Internally... I'd think it was hilarious. Being told to fuck off by a 10 year old who you raise and make food for everyday is low key hilarity. But to start I'd ask them why they said that. Why it's not an appropriate way to speak and how that can be hurtful and why cursing isn't something you don't do all the time. We'd move to punishment later. It's not that big a deal, children are emotional.

10 days total lock down, no games, no phone, no friends over, no going out except for school.

No candy for a week bro

No Minecraft for a year

10 lashes.

When I was 10, it would have meant the wooden spoon and a mouth full of soap.

My parents would make us do not normal chores when we would get in trouble, like cleaning the baseboards or cleaning grout

In my household we would have gotten our asses whoop, no talks, No chores, no grounding. Nothing. Just a ass whooping.

Immediately take away everything and only have books in their room. You wanna act like a disrespectful person? I'mma treat you like a disrespectful person. I won't hit you. But I won't let that shit slide. And then I would make them clean the bathrooms, ALL OF THEM. I would also make them do chores.

For a fucking month. Or hell whenever I get tired of it. And I want them to understand that you hurt me when you swore at me. You disrespected me. You disrespected this family. And most of all, you disrespected your mother (or father or other parent).

Punishments are counter productive. By punishing, you are just asserting dominance and control, and there will be a disconnect between you and your child. Punishments cause fear and contempt. It’s better to explain to the child how you feel when they say hurtful things and try to understand what caused the reaction. If you take a moment to calm down and open your mind you might see the childs point of view and learn. Do you want a child that learns to obey and stay calm at all times?