Terminar de...
You would think that "I finished building it" would be translated as "Terminé constriuirlo" but instead it's "Terminé de construirlo". Why do verbs sometimes use "de" in this kind of construction where it doesn't appear to serve a purpose? A verb with a similar meaning is "acabar", but when "de" is added to that verb, it changes them meaning slightly - "to have JUST (done something"). But this doesn't appear to be the case with "terminar". Maybe I should just accept this and move on, but my analytical background makes me want to know why!
1 Answer
All languages have what I call "post positions" following certain verbs. Post positions are prepositions that follow the verb.
In addition to what Bosquederoble gave you: listen to, look at, Put out (the fire), etc.
In Spanish you have terminar de, acabar de, asistir a, empezar a and others. Wait till you get to "acabar por"
Here is a link to verbs with prepositions. (a big bunch of them)