Negative questions and tag questions ?

[Assassin]

- If somebody asks me: "Don't you have school today?"
If I answer: "Yes, I do (is "do" right or don't?)", does it mean that I don't have school today ?
- If somebody asks: "Snow is black, isn't it?"
If I answer: "No, it isn't", does it mean that I don't agree ?

[Anglika]

#1 It means that you do have school today. If you do not have school, your answer will be "No, I don't have school..."

#2 Correct

[gayanah]

- If somebody asks me: "Don't you have school today?"
If I answer: "Yes, I do (is "do" right or don't?)", does it mean that I don't have school today ?
- If somebody asks: "Snow is black, isn't it?"
If I answer: "No, it isn't", does it mean that I don't agree ?

Hello
I think your short answer Yes,I do for the first question is right. It means you don't have school.
Your answer for the second question is also right.
Not a teacher.