注意：在肯定句中，非延续性动词如come，go，leave，borrow，buy，die，join等的完成时不能与时间段连用，若要接时间段状语，则应换成相应的延续性动词或状态动词。但在否定句中，非延续性动词的完成时可与时间段连用。 ①I have bought a new car.我买了辆新车。 ②I have bought a new car for two weeks.(×) →I have had the new car for two weeks.(√) 我买了这辆新车已经两周了。