My Spanish skills aren't what they used to be. There's one thing in particular that confuses me. I don't know when to use the letter e or the letter a in certain words. Lemme explain. If you're telling someone to listen, would you say "escuche" or "escucha"? If you're telling several people to look at something, do you say "miren" or "miran." etc. etc. So basically what I'm asking is what is the rule for using these e's and a's?