http://www.engvid.com "I have eaten." "I had eaten." What's the difference, and when do use each form? In this important grammar lesson, learn how to distinguish between past perfect and present perfect. You'll learn the correct form of each tense, and when each should be used. Then take the quiz at http://www.engvid.com/present-perfect-or-past-perfect/ .
آی-ویدئو