Possible Predicates:"falls" (e.g., "The pencil falls.")"is pulled downward" (e.g., "The pencil is pulled downward by gravity.")"accelerates" (if we are describing the pencils motion during a fall)"rests" (if we are describing a pencil at rest on a surface, while gravity still acts upon it)In essence:The predicate tells us what gravity is causing the pencil to do.Therefore, depending on the context, the predicate will describe the action of the pencil, as it is being effected by gravity.