Spanish language Q&A Forum

In this exercise, what exactly is the reason to prefer "libros buenos" rather than "buenos libros"?

Does the verb "costar" always take the preposition "a" when referring to the person OR entity upon which the cost is falling? Here, "los gobiernos" are not people or favorite pets, yet the personal a is apparently indicated. 

Hi, I have been told (by two different Spanish people) that 'Me estoy leyendo...' signifies 'I am reading (right now)...', but I cannot find any lessons relating to this.  Is there such a lesson?

Mi madre no piensa que yo vaya a terminar el curso de fotografía.My mother does not think I will be able to finish the photography course.
“…vaya a terminar..” means …going to finish…” It does not mean “…be able to finish…” but, hey, I may be translating too literal?

It has been suggested to me that "deber" in the present tense (and other tenses as well) can be best translated as "must" and that "debería" (in the conditional tense) can be best translated as "should". Is this a reasonable supposition, or would you prefer to put forth a better way of translating this (sometimes enigmatic) verb?

o or ó for “or” in Spanish?

I notice that in the test question "iba" was used, but in the example here the preterite "fueron" is used. How do we know which to use and when?

I thought that Habrian is in the future, but I have seen it used many times as not in the future. Are these two interchangeable?