Guys I'm having trouble with my vertices, I created a model in polygons and I seem to have double vertices and double faces all around the model. If I try to extrude something I have to select the face with the marque tool because there's a replicated face behind it. Usually when you model theres only one face and one vertice, but somehow I I managed to double my faces and vertices. I'm not quite sure why this is happening, can anyone please help me out?