to try to teach someone something that is difficult for them to learn due to their age or experience
intentar enseñar a alguien algo que es difícil de aprender debido a su edad o experiencia (intentar ensenyar a algien algo ke es dificil de aprender debido a su edad o experiencia)
"It's hard to teach an old dog new tricks, but I'll try."
"Es difícil enseñar a un perro viejo trucos nuevos, pero lo intentaré." (Es dificil **ensenyar a un perro viejo trucos nuevos**, pero lo intentare)
to deceive someone by creating a fake online identity
to stay brave and strong in difficult situations
at the most advanced position in a field
a moment of sudden discovery or realization
success for someone inexperienced
to suffer because of one’s own mistake