...........As If He Was Supposed To
 

I wrote this sentence in Spanish and then in English in a notebook some time ago, but now I question if it is even grammatically correct or even a correct translation.


Enrique aventó/lanzó/tiró la basura por la ventana como si suponía que debiá hacerlo
Enrique tossed/threw the trash out of the window as if he was supposed to (someone told him to do it and he complied with the directive)


Other translations come to my mind, but I have no idea if the original that I wrote above or any of the following are correct:

Enrique aventó/lanzó/tiró la basura por la ventana como si suponía que debiera hacerlo

Enrique aventó/lanzó/tiró la basura por la ventana como si supusiera que debiá hacerlo

Enrique aventó/lanzó/tiró la basura por la ventana como si supusiera que debiera hacerlo

Input and explanations are appreciated.

There are two separate problems, one with your original sentence and one with your translation.

First, in your original sentence you wrote "... como si suponía ...". This is incorrect: only past subjunctive follows "como si". Of your alternatives, the second and third have past subjunctive "supusiera" after "como si", which is correct.

Second, "to suppose that X" is a valid equivalent of "suponer que X", but "to be supposed to (do X)" is NOT a valid equivalent of "suponer que X".

A better translation of your alternative sentence:

Enrique aventó/lanzó/tiró la basura por la ventana como si supusiera que debiá hacerlo.

would be something like:

Enrique threw the trash out (of) the window as if he supposed/thought that he was supposed to do so.

"To be supposed to (do X)" usually implies either obligation/responsibility, or else it implies what was expected or planned.

For example, these sentence imply obligation/responsibility:

a. Juan was supposed to clean the room after finishing the project.
b. Maria was supposed to pay the bill last week.

While this sentence implies what is expected or planned:

c. I am supposed to visit my mother this weekend.

Possible translations include:

a. Juan debía (OR tenía por deber) limpiar el cuarto después de completar el proyecto. (OR) A Juan le correspondía limpiar el cuarto después de completar el proyecto.
b. María debía/tenía por deber pagar la cuenta la semana pasada.
c. Debo visitar a mi madre este fin de semana.

Thank you, wrholt, for the input, explanations, and examples.