Can I say? We don't say: - I guess this is two men's house. - I guess this is three boys' house. - I guess this is some boys' house. We say: - I guess this is the house belongs to two men. - I guess this is the house belongs to three boys. - I guess this is the house belongs to some boys. So, can I say: - I guess this is the house of two men. - I guess this is the house of three boys. - I guess this is the house of some boys.