Verb + interrogative

Question

Hello everyone,

I would like to know how to translate phrases like this:

'In order to know where they are, bats use sounds.'

I asked somewhere else and they said it should be:

'Para saber EN dónde están, los murciélagos usan sonidos.'

Is that 'en' required and is it always that preposition or does it depend on which interrogative pronoun/verb I use? Why is it used? I'm just a little in the dark on this subject at the moment.

Thanks for reading and answering my question! Hope it's not too stupid. Greetings from Holland!

Welcome to SpanishDict. - rac1, Feb 13, 2017

Answer 1

En could be used here (not grammatically incorrect), but it´s not necessary and the sentence would sound more natural without it.