the perfective aspect indicates that an action, situation, or event is seen as complete at a particular time. The perfective verb group consists of a form of ‘have' and a past participle. For example, in the sentence ‘The voters have decided it's time for a change', ‘have decided' refers to a point in time before now. In the sentence ‘After we had finished all the food, more people arrived', ‘had finished' refers to a point in time before ‘more people arrived'.