Well, you should use examples. One example most people understand is in reference video games. So, you have monster objects and monsters have certain attributes like color, size, shape, number of arms, and so forth. Then some monsters have different "abilities" like breath fire, shoot guns, so on and so forth. These are silly examples but easy to understand. I think it is easier to explain to a novice than all this business about "squares," "circles," and so forth.
