"tendría que"
 

I have the passage below, and the phrase "tendría que" is translated as "should have", which makes perfect sense in the context. But why is "tendría" used? This seems to mean "would have" and when I try to research it, I find nothing suggesting it can be used to mean "should have".


"—Estaba preocupado por ti, ¿ha sucedido algo? —me preguntó nada más abrir la puerta.

—Mi madre está peor. Apenas salgo del hospital, tendría que haberte avisado. Lo siento —le dije.

—No tienes que disculparte de nada. Ella es lo más importante ahora."

The translation is "should have".
In this case, "tener que" is the same as "deber (de)"
When you say in present tense: "tengo que avisarte", in English you would say "I must let you know".
"Tener que hacer algo" means to have an obligation (either formal or moral) to do something.

- Tengo que hacer la tarea. -> I must do my homework.
- Tendría que hacer la tarea. -> I should be doing my homework.
- Tenía que haber hecho la tarea. -> It was my obligation to do my homework and I didn't do it.
- Tendría que haber hecho la tarea. -> I was doing something else at the time when I was supposed to be doing my homework.

In your example, the speaker was too busy taking care of their ill mother to tell the other person about it, so they're apologizing for not fulfilling that moral duty of telling about their situation.


For a "would have" translation, we would have had a conditional sentence like this:

- Te habría avisado, si hubiera tenido tiempo. -> I would have let you know, if I had had time.
With this kind of construction, you need the situation that would have made the action happen.
- Si hubiera salido antes del hospital, te habría llamado. -> If I had left the hospital earlier, I would have called you.
- Si mi madre hubiera mejorado, lo habrías sabido. -> If my mother would have been better, you would have known.