•  zero conditional 
  
  This conditional refers to a situation that is always true (universal truths): If you freeze water, it turns into ice.
  Example
  • If you freeze water, it turns into ice.
    Si congelas el agua, se convierte en hielo.
  • If I work too much, I get tired.
    Si trabajo demasiado, me canso.
  • If I have time, I usually go to the movies.
    Si tengo tiempo, generalmente voy al cine.
  • If she eats hamburgers, she gets an allergy.
    Si ella come hamburguesas, le da alergia.
  • If they come here, they always bring a present.
    Si ellos vienen aquí, siempre traen un regalo.
  • If she doesn't know the answer, she keeps silent.
    Si ella no sabe la respuesta, se mantiene en silencio.
  • If we don't go out on Saturdays, we rent a video and stay home.
    Si no salimos los sábados, alquilamos un video y nos quedamos en casa.