About learning Spanish!
It is not as simple as where would you want to live the majority of Spanish is spoken in South America - where most Europeans don't stand a chance in hell to get a job unless they can get a work permit in that specific country!
Why not Portugese, Brazilian airlines are hiring?
I also know Colombian airlines hiring, but unless European is married to someone from that nation, there is not a peanut in hell that will get a job with low hours in South America, so why learn Spanish (or Portugese) if you can't apply for the majority of work there?
There as to be some substance to advice given, I could apply for job in South America, because my wife is from a country there, but this is not a simple step, it gets pretty complicated. License conversions, skills tests and theory test all in Spanish + this is not for free, expect another few thousand pounds - and than you can apply for jobs there.
Many there bond you for 3 - 5 years, and pay your TR and as a FO you might complain about what FR pays you, well half the FR salary - and you see what you get.
Of course it is much cheaper to live in South America! (some wise person who has never been there might say!)
No it isn't, if you want to live in a decent house, in a safe area, and have a normal standard of life. A Toyota is not going to be half price of price here in Europe, a can of beans will not be sold for 5 pence either.
(Of course the Burritos and Tequilas on the corner shop will be much cheaper than in the UK, but you can't just live of this, can you?)
So in the end you can learn as much Spanish as you want, but you can only have a chance to work for a Spanish airline, or you have to find someone to marry, go and live 1 year in that country, convert your license - might be cheaper paying your own TR in the end.
I do agree it is useful to know multiple languages, but it is very limited what use you might get out of it, even if Spanish is spoken equal to English in the world, it will not significantly help you get a job, unless of course you have the right to work in the specific country you target. There must be a plan if you want to improve your CV, a goal / a target - why do I want to spend months learning Spanish unless I intend to go and live there, at the level we require to be able to do technical interviews and tests. It is not just a porky pie level, you need to get a little in depth in the language. Not just hello, where is the nearest hotel Miguel!
I would say within EU, Germany is probably the strongest economy, so if they do hire "foreign" pilots, I would assume that would probably be the better option.