Unit 92 - Imperatives

With the imperative in Italian you need to change tracks, for example if you say to a person you know eat the pizza, you would say mangia , if you were commanding them to do it instead of tu mangi, however if you say to a person eat the pizza, you would say mangi, so you are switching from a to i in this case and in the last from i to a for the informal in the first case and formal in the second case for the verbs ENDING in are, what can you tell me for the other verbs that end in ere and ire?