Quote:
Originally Posted by
why 
Learn a Romance language because if you learn one the others all become much, much easier and the Romance-speaking countries are the only countries in Western Europe where English is not widespread. Plus because of their linguistic proximity to Latin they will also improve your formal and technical English.
Trying to learn Mandarin for business reasons is dumb especially if you're trying to learn it in the US at a university.
Quote:
Originally Posted by
Texasmade 
If you're in accounting, the only language you need to know is English. US GAAP and IFRS are all in English and those are the 2 largest reporting standards.
+1. Or, again, learn a language simply for the underlying cognitive benefits, not necessarily with the intention of doing much with it or speaking with native speakers beyond what Globe mentioned. Bilingual speakers almost always do better on mathematical tests, spatial, perceptual, and analytic reasoning, etc. You don't gain these consciously, but they develop over time as your brain adapts new pathways required by the second language that were not in the first.
So, in this way, why's idea seems a good one. Chinese, Japanese, or Korean in theory would be good for your brain as they require very different neural patterns than English, but before you'd really feel any of the effects you'd have to become fairly fluent... which probably won't happen or would require an enormous effort with little reward.
Given that the OP already has Spanish, another romance language (or even Latin itself) would be the best bet.