I am studying Spanish. In my text book it says:
qué = what? para qué es eso = what's that for?
Why does one example use "
para" and the other does not?
It is the same as in English.
What? = ¿que?
What for ? = ¿para qué ?
"para" is a preposition that in this case gives the sentence the meaning of "purpose" or "an end" and is equivalent in most cases to the english preposition "for"
In the same way sometimes it denotes "direction" like :
¿dónde? = where?
¿para dónde? = which way?
and another similar case is this:
¿quién? = who?
¿para quién? = for whom?
These are the most common meanings but it has many others that you will learn slowly but if you want to take a look at the RAE dictionary here is the link