Hola Isaac. una buena pregunta. May, Might y Could son "modals" que se utilizan para habilidades, posibilidades y pedidos. ejemplos: habilidades I can sing (only expresses an ability to do something.) I could sing but I'm tired (When you can do something, but you won't for some reason) I may sing later (expresses a good possibility of doing something in the future) I might sing later if I feel better (a conditional- expresses a chance to do something so long as there is a condition. Pedidos: Can you lift the chair (asking someone if he or she can do something. This is informal.) Could you lift the chair (a polite way of asking someone to do something? (no puedes utilizar may o might) Permiso. Can I go now? (an informal way of asking permission.) May I go now? (a polite way of asking permission) (no puedes utilizar could)