"HOW FAR IS IT...?" OR "HOW LONG DOES IT TAKE...?"
These two questions often cause a lot of confusion for Spanish speakers. The main thing to remember is that "HOW FAR IS IT?" is always connected to distance (KM) and "HOW LONG DOES IT TAKE?" is always connected to time (hours, minutes, seconds).
So, for example: How far is it from Madrid to Barcelona? Answer: It is 600 km (The "it is" is very important in this case). How long does it take to drive from Madrid to Barcelona? Answer: It TAKES 6 hours. (the verb "takes" is important here).
Hope that helps!
If you like this, here are some more:
Soy el director de Daniel Smith + Partners. Tengo más de 10 años de experiencia enseñando inglés a españoles.