Present perfect

Present perfect

The present perfect is formed from the present tense of the verb have and the past participle of a verb...

Lesson 
http://www.englishpage.com/verbpage/presentperfect.html

Vocabulary
http://www.aprenderinglesfacil.es/2008/06/presente-perfecto-present-perfect-tense.html

Grammar
http://www.studyspanish.com/lessons/presperfect.htm

Exercise
http://www.englisch-hilfen.de/en/exercises/tenses/present_perfect_statements.htm

Video 
http://www.skypeenglishclasses.com/skype-english-blog/videos/english-present-perfect-video-with-exercise/