All those who have ever tried to learn a foreign language, specially those who have had the luck to have experienced it "on-site", are likely to agree with me when I say that a language is not merely composed by a bunch of grammar rules. Intonation, manners (try to picture Italians or Argentinians talking without their hands), and facial expressions play their role as well. However, no language is likely to be succesfully embraced without the learner´s interest in the exploration of the thinking of the individuals responsible of shaping the culture itself. And there is where the major gains of learning a language reside.
Gains? Yes. Both from a personal or from an economic perspective. From a personal perspective, besides the potential benefits for you brain, understanding the way people behave is unlikely to be achived without having some knowledge on their cultural background, for which having a basic knowledge on the language would certainly be an asset.
From the cold economic perspective, learning a foreign language would be well described by the well known phrase "put your self in the shoes of the customer", wisely recalled on an article published at the BBC news site ("Firms ignore the foreign language internet at their peril").
In a world where it only takes one flight (one click) to go from one continent to another, the productivity of our work relies more and more on how developed our managerial skilles are. Thus, from my perspective, embracing foreign languages is likely to be benefitial. What do you think?