Miguel es un cocinero experto y, si dice que haces algo mal, será verdad.Miguel is an expert cook, and if he says you do something wrong, it must be true.
La profesora quiere que aprendas. No te enfades cada vez que dice que haces algo mal.The teacher wants you to learn. Don't get angry every time she says you do something wrong.
El mecánico dice que haces algo mal, que, si no, el carro no estaría siempre averiado.The mechanic says you do something wrong, that othewise the car wouldn't be always broken.