Annata Terranova: I am interested in learning a new language. I have considered both Spanish and Chinese, but am curious which language everyone would recommend as being the most useful to learn and why?
I'd recommend that you learn Spanish, especially if you're living in North America or Europe.
Here in the U.S., Spanish speaking communities aren't restricted to the Southwest, Florida, New Jersey, and New York City. These communities have spread throughout the southern part of the U.S., and are working their way further north.
This means that many service related jobs, as well as construction, are seeing more Hispanic workers.
Imagine walking into a Hispanic themed restaurant to order an ice creamed based "Golden Cadillac" drink. You see the cone shaped galiano bottle in the bar, which is one of the ingredients. In response, the bartender asks, "martini?" Speaking Spanish to them would allow you to spend more time finding out if that recipe is available, and less time trying to bridge the language barrier with statements like this: "Galiano! Ice cream! Me no want martini, no!"
If you decide to go on a multiple-country trip south of the Rio Grande, you won't need to learn a third language. Spanish would get you through; even if you're in Brazil, where they speak Portuguese. Simply speak Spanish to them, and let them speak Portuguese to you. Many Brazilians also speak Spanish.
Either way, the language barrier would be minimal to none. Picture this. You're partying at Ipanema, in Rio de Janeiro, Brazil. You're speaking to a Brazilian in Spanish, and the Brazilian is speaking to you in Portuguese. In the middle of the conversation, the Brazilian compliments your Portuguese.
You could also use Spanish in Western Europe. Spanish, Portuguese, French and Italian evolved from Latin. Even though they've deviated, you could still hold a conversation with someone in France, Italy, and Portugal without speaking their native language.
Imagine another scenario. You're talking to a French woman who's speaking Italian; you guys are in Italy. You make a comment, in Spanish; that it's neat that you guys could converse with each other despite speaking different languages. She responds, in Italian, that there's no way you could do that.
That's ironic, but both scenarios are based on actual experiences.