Mary's house or The house of Mary ,the son of my grandpa or the grandpa's son
I'm confused can you explain me with examples. I'll thank all my life.I want to explain and other guess
who I am talking about?I want to explain and other person guess who I am talking about?the son of my grandpa or the grandpa's son

Question

Mary's house or The house of Mary ,the son of my grandpa or the grandpa's son
I'm confused can you explain me with examples. I'll thank all my life.I want to explain and other guess 
who I am talking about?I want to explain and other person guess who I am talking about?the son of my grandpa or the grandpa's son

Answer

It would be Mary's house because your directing the house to who owns it.

Son of your grandpa? Did you mean your uncle then? Or did you mean you dad.