Most children go through a phase where they treat irregular verbs like they are regular. They notice the larger pattern and apply it to all verbs: in the past tense words attach an –ed at the end. When they notice this pattern, they start making these over-regularization errors.
“I putted my toys away.”
“My brother eated the cake.”
“I teached grandma to use the iPad.”
Although there are just 180 irregular verbs in English, the most commonly used verbs are irregular. In fact, 7 out of 10 times we use a verb, it’s an irregular one. There is no consistent pattern to simple past or past participle of irregular verbs. They just have to be learned.