Present simple: to talk about regular activities, states and permanent situations, and preferences:
I have breakfast at 7 o’clock. Present continuous: to talk about activities and events taking place at the moment of speaking, and temporary situations: The manager is talking to the customer.
Past simple: to talk about activities and events that started and ended in the past:
Yesterday we played tennis in the garden.
Present perfect: to talk about actions and events which ended in the past but we don’t know or it’s not important when exactly they happened: I have never swum there.