(que) optional?

Question

Can you please elaborate a bit on when the "que" is necessary in "gracias a que"? Is there a reason it's needed for nuestros padres but not for la colaboración?

Answer

Hola R,
when we use "gracias a que..." what follows is a subordinate sentence (que is compulsory). But gracias a can also be simply followed by a noun, in which case you don't need "que". For example, you can say:

Pudimos comprar la casa gracias a la ayuda de mis padres. 
We could by the house thanks to my parents help.

or

Pudimos comprar la casa gracias a que mis padres nos ayudaron.
We could buy the house because my parents helped us (=thanks to my parents helping us)

I hope this clarified it.
Saludos
Inma