Can you please give me more information about this? I don't understand what shadows you are referring to.
That means you need to do more research and study in the arena of lighting. Look at the wall behind your subject. Do you notice well defined lines? If I may be so bold, that's what Light Guru is referring to. In portraiture and generally speaking, the transition from light to shadow should be gradual. If this is natural light from an open window, one method to reduce the harsh shadow is to diffuse it by by of placing a diffusing material between the light source and the subject. A white bed sheet, a clear shower curtain or anything to knock down the intensity of the incoming light can work wonders.