http://www.englishexercises.org/buscador/buscar.asp?nivel=any&age=0&tipo=any&contents=irregular+verbs#thetop


http://www.englishpage.com/irregularverbs/interactiveirregularverbs1.htm


http://www.englishmedialab.com/GrammarGames/New_Snakes_%20Ladders/Past_simple_tense.html


http://www.englishmedialab.com/GrammarGames/perfectpast/irregular%20past%20spelling.html