Why are there regular past and irregular past ?
Even in irregular past, there are different forms,
e.g. break changes to broke;sing changes to sang;buy changes to bought
Any rules behind? Is there any simplest way to explain these cases to a P3 student?
Many of the ireegular verbs are derived from Anglo-Saxon and Viking languages, so they don't follow the pattern of the regular verbs. If you click on a verb in our irregular verb list, you'll see all the verbs that follow the same pattern: