I think you can teach people a technique - you can teach them how to use their voices, how to breathe properly, how to move their limbs a certain way. But to actually explain how one performs comedy or drama or tragedy isn't the same as the movements one makes.
Judi DenchIn the theatre you can change things ever so slightly; it's an organic thing. Whereas in film you only have that chance on the day, and you have no control over it at all.
Judi Dench