Can u survive a broken neck?

Well, my boyfriend broke his neck in a car accident. Hes in the hospital, and hes still alive, its possible he might die though.. My friend says: if yew broke yur neck that would mean you completely detached your head from your body so that would mean his head is not attached to his body, so he probably didnt break his neck. But apparently hes still alive?? Im really confused, so is it possible to survive a broken neck? and how is it possible?