"tremble" can be used in human beings and on inanimate objects. For example: She trembled in fear when she saw the man with a knife (humans) ... We felt the ground trembled for a moment and knew later that it was a magnitude 5.1 earthquake. "Shudder" can be used for both also "shiver" commonly used with humans. Especially when reacting to a cold temperature. "shake" can be used with both. When used with inanimate objects, they are often associated with earthquakes or forces of nature