I distinguish between sentences like (1) Last Thursday we drove from Wellington to Waikanae and (2) Last Thursday my copy of Aspects of the Theory of Syntax remained on my bookshelf. Sentence (2) has the subinterval property. If it is true at an interval t it is true at every subinterval of t. (1) lacks this property. (1) reports an event. (2) reports a state. Events do not have the subinterval property but states do have it, and so do objects. If something is a linguist at an interval t then that person is a linguist at all subintervals of t. I argue that 'exists' applies to things which have the subinterval property, and 'occurs' applies to things which lack it.