For home and voluntary: You have got in “Irregular verbs” link a video embedded from You Tube to learn the past tense verbs. Listen carefully to the pronunciation. You can have a look at it whenever you want. Remember that a good way to learn irregular verbs is by repeating them out loud as many times as possible.
“Irregular verbs” http://www.youtube.com/watch?v=gK12tjcqpsM&feature=related
If you want to learn some past tense verbs, click on this.