TO CONJUGATE THE PRESENT PERFECT TENSE, YOU NEED TO USE THE PAST PARTICIPLE OF ALL VERBS. LISTEN TO THE PRONUNCIATION OF THESE IRREGULAR VERBS IN SMPLE PRESENT, SIMPLE PAST AND PAST PARTICIPLE
http://www.manythings.org/repeat/1.html
EL TIEMPO PRESENTE PERFECTO CON «HAVE YOU EVER…?»
COMPLETE Brad Pitt´s BIOGRAPHY CHOOSING THE SIMPLE PAST OR THE PRESENT PERFECT
http://www.englishexercises.org/makeagame/viewgame.asp?id=3081
WHAT TO REVIEW BEFORE THE FINAL EXAM
TIEMPOS VERBALES QUE PRACTICAMOS
http://www.gingersoftware.com/grammarbook/verbs/verb-tenses/
MORE ABOUT THE SIMPLE PAST
http://www.englishpage.com/verbpage/simplepast.html
TODAVIA TIENES DUDAS SOBRE EL COMPARATIVO Y SUPERLATIVO? VE ESTE BLOG!
http://myenglishproject.wikispaces.com/Comparative+and+superlative+adjectives
o checa esto!
BLOG QUE TAMBIÉN USASTE
http://meifsegundopractice.blogspot.mx/