• English verbs can be placed in various classes depending on their meaning. In other words, they can be classified “semantically.” The most important of these classes are: event verbs and state verbs.
• Event verbs refer to events—happenings that begin and end at a definite time. For example, the verb build as it is used in the sentence Jack built a beautiful house by the beach is an event verb.
• State verbs refer to states—conditions or situations that are seen as not having any definite beginning or end; they are seen as permanent, in other words. For example, the verb own as it is used in the sentence Jack owns a beautiful house by the beach is a state verb.
• Some examples of event verbs: eat, break, fly, fall, begin, watch, boil, drink, explode, kick
• Some examples of state verbs: work, be, live, know, believe, contain, belong, matter, last, depend, deserve
• It is important for students, and teachers, of English to have an understanding of the distinction between event verbs and state verbs because without a grasp of this idea, it is difficult to understand or to explain the correct use of the basic verb tenses. For example:
(1) The present perfect is commonly used with state verbs and an adverbial referring to a period of time coming up to the present, as in Jack has worked for the same company for seventeen years. However, the present perfect of an event verb is not commonly used in this context and if it is, in a sentence like Jack has eaten in that restaurant for six years, there is an important change of meaning: the verb now refers, not to a constant state, but to a series of repeated events. (The present perfect continuous is more commonly used to express this sort of fact as in, Jack has been eating in that restaurant for six years.)
(2) State verbs are not normally used with any of the continuous tenses. In other words, they are "non-continuous" (or "non-progressive"). Sometimes, these non-continuous verbs can be put into a continuous tense, but when this happens there is a change in meaning as well as a change in tense. For example, Harry thinks reading books is a waste of time refers to Harry's permanent opinion but in Be quiet. Harry is thinking the verb refers to a temporary activity with a definite beginning and end.