I want to learn a new language. I have some money to spare to buy some books and courses, and I have lots of free time. I'll probably study Computer Science, Economics or Engineering, and I'm looking for something that could help me in the future.

I already know Spanish (my mother language) and English (duh), which language should I learn next?

Considering China's rapid economic growth, I would say Mandarin would be useful and relevant to each of those areas of study.

Netherlands has the strongest economy in Europe, Germany has the largest. I'd recommend Deutsch, spoken by many and somewhat easy to understand and learn Dutch. Also my teacher used to say it was the language of math and numbers.

As a spanish-speaking Economics student, I suggest you Chinese.

Don't learn another language because you feel you need to. Do it because you like it.

I suggest Chinese or Japanese because you get to learn thousands of characters, which is pretty fun.

Im Japanese, and im studying calculus, stats, and macro economics in English.
English is good to learn for science to me :)

Please spread.Japan and Korea issues.

http://www.youtube.com/watch?v=FaOCQ9AQyP0&feature=player_detailpage

If you wanted to be more familiar with medical terms or biological names try Latin and Greek

If not, French is the next best language or Spanish
I heard in France, they have lots of good pharmaceutical companies plus grandes ecoles for engineering
and IUPAC itself was established in Switzerland

Germany has always had the best hub for engineers and all the heavy industry and manufacturing sector

Want the make oil deals, then speak Arabic in Dubai!

Or just become another tech guru in Silicon Valley. Hire translators to speak on behalf for you.

Jap or Mandarin if you need to go down to the operational and technological parts components factories there