Listen to a few sentences describing the actions of the person shown. The sentences are then written in the past-tense for you to see and identify the simple past-tense verbs. Regular and irregular verbs are then defined with sentences...

Teach your class to pay attention to how a word looks and sounds when working with conjugating irregular verbs into the past tense. The video provides several examples of incorrectly and correctly spelled irregular verbs.

These are the most regular of the irregular verbs; while they don't behave exactly like regular verbs, like present tense 'walk' become past tense 'walked', they do maintain the '-ed' sound. It's just spelled differently.