Click the above link for a lesson on the Present Perfect.
Present Perfect Tense:
The present perfect is a grammatical combination of the present tense and the perfect aspect, used to express a past event that has present consequences. The term is used particularly in the context of English grammar, where it refers to forms such as “I have left” and “Sue has died”. These forms are present because they use the present tense of the auxiliary verb have, and perfect because they use that auxiliary in combination with the past participle of the main verb. (Other perfect constructions also exist, such as the past perfect: “I had eaten.”)
Analogous forms are found in some other languages, and these may also be described as present perfects, although they often have other names, such as the German Perfekt and the French passé composé. They may also have different ranges of usage – for example, in both of the languages just mentioned, the forms in question serve as a general past tense, at least for completed actions. In English, completed actions in many contexts are referred to using the simple past verb form rather than the present perfect.
English also has a present perfect progressive (or present perfect continuous) form, which combines present tense with both perfect aspect and progressive (continuous) aspect: “I have been eating”. In this case the action is not necessarily complete; the same is true of certain uses of the basic present perfect when the verb expresses a state or a habitual action: “I have lived here for five years.”