Infinitivo compuesto' to express actions in the past which did not happen?

Question

In my book 'Gramatica de uso del Espanol C1-C2', unit 71 is dedicated to `infinitivo`, and there are two sentences using `infinitivo compuesto`: > No quereis ir? **Haberlo pensado** antes. > Que esta;s cansado? **Haber descansado** cuando pudiste antes. To me, it seems it is used to express something which should have happened/been done in the past, but hasn't. What is this form and where can I read more about it? I tried to search for it but as I don't know the grammatical term, I couldn't find anything.

Answer 1

Infinitivo Compuesto

Estructura

Infinitivo de haber + participio del verbo principal.

1. Ejemplo: haber + comido (comer)

 haber + ido (ir)

 haber + bebido (beber). 

Usos comunes

1. Expresar una acción pasada o anterioridad:

1. Indica que la acción del participio ya se ha completado en el momento en que se habla o en relación a otro verbo. 

Ejemplo: Siento mucho no haber ido a la fiesta. 

Al haber cruzado la calle, vimos a Pedro.

2. Referirse a un arrepentimiento o reproche:

Se usa para expresar pena o crítica por algo que no se hizo en el pasado. 

Ejemplo: Tendrías que haber llamado antes. 

¡Debiste haber cerrado la ventana!

I see that the second use matches your examples.

Answer 2

I believe what you’re looking for is the “infinitive perfect” form. This is when the verb “haber” is used with another verb conjugated in the past paticiple form. It sounds complicated, but pretty much “haber” is left in it’s infinitive (unconjugated) form followed by the other verb conjugated with the “ado” (-ar verbs) or “ido” (-er and -ir verbs) ending. Here’s a quick example: “Me gustaría haber ido.” (I would have liked to have gone.) If you want to learn more about how to use it, you can look for it in your textbook as "infinitive perfect," search online now that you know the term, or get help from a tutor.