To be
My mother are beautiful.
My mother is beautiful.
My mother is the aunt of my sister.
My mother is the mother of my sister,too
My father don´t like yogurt.
My father doesn´t like yogurt.
Peter and Mary is my brothers.
Peter and Mary are my brothers.
My uncle is bigger than a tree.
My uncle is smaller than a tree.
My grandparents doesn´t know hoe to make cake.
My parents don´t know how to make cake.