"BARKING UP THE WRONG TREE", ¿LO CONOCES?
This is a very common idiom in the UK and can be used in a variety of different contexts. Probably you are familiar with all the word except "barking" which is "ladrar" in Spanish?
So, what does this idiom mean?
As is common with most idiomatic expressions it has got nothing to do with words it contains = it is not about "trees" or "dogs". In fact, it is a way to express the idea that someone has misunderstood or is mistaken about something.
For example: "You are barking up the wrong tree if you think that my aim is to be an engineer".
Hope that helps!
Soy el director de Daniel Smith + Partners. Tengo más de 10 años de experiencia enseñando inglés a españoles.