The key depends on whether your grandfather has an inheritance. If you have an inheritance, you must use it to pay off your debts before you can inherit the rest. In other words, use his own money to pay off his own debts.

If you don't inherit your grandfather's inheritance, such as real estate, even though you are a child, you are not obligated to repay him.

Whether children pay debts for their parents depends on whether they get their parents' property. If they get property, they must pay their debts first.

In other words, this kind of debt is actually very clear and has nothing to do with blood.