If you mean that there are those certain dark/shadow spots, and you don't want them there, it is likely that there are 2 or more faces in the same place. Try in smooth/flat shaded all view selecting object -> faces and then delete the face where your shadow appears. If there still is another face behind you deletion, you have solved the case (and you can just delete your unwanted faces to prevent those shadows), if not, press CTRL + Z to undo, and post again...