1. If your grandparents built (bought) before they got married, the house belongs to your grandfather's personal property before marriage, and your grandmother and your aunt are the legal first-order heirs, you can also inherit the property through subrogation inheritance (on behalf of your father).
If the house was built (bought) by your grandparents after marriage, it belongs to their father. According to the principle of "analyze the property first, then inherit", half of the house will be given to your grandmother, and the other half will be inherited by his legal heir as your grandfather's inheritance.
Second: if your grandmother died without a will, it will be inherited by your grandmother's legal first-order heir, your grandmother's legal first-order heir: your grandmother's children.
Xian Dan: If your grandmother dies, the will will tell her two children. The principle of inheritance is: there is a will to be carried out according to the will, and there is no will to be carried out according to the law. The effect of the will is higher than the legal inheritance.
Fourth: If you go to court, you can't take advantage of it, because if this house is the property of their husband and wife, then she accounts for more than half of the property. According to the principle of taking care of the legitimate rights and interests of women and the elderly, it is difficult for you to take advantage.
On the important elements of the effectiveness of oral will;
First: it must be made in an emergency.
Second: there must be more than two people who are not interested.
So your grandfather's oral will is invalid.
According to the fifth paragraph of Article 17 of the Inheritance Law, the testator may make an oral will in case of emergency. An oral will shall be witnessed by two or more witnesses. After the emergency is lifted, if the testator can make a will in written or recorded form, the oral will made is invalid. If Mr. Zhang's father doesn't make an oral will in an emergency, and he doesn't make a will in written or recorded form after the emergency is lifted, then the oral will is invalid.