Answer:
This phenomenon is called overgeneralization.
Step-by-step explanation:
Overgeneralization is a gramatical mistake, that happends when a person applies a grammatical rule to cases that it that does not apply. Learning grammar means to know when to apply which rule, this takes time and so people can make mistakes. In this case they apply the rule that works for past tense regular verbs, an use it with irregular verbs.