If you do not have a second language you are operating with a handicap.
More and more people in the U.S. speak Spanish, so this makes Spanish the logical choice.
The reason I say you are at a disadvantage is that the Spanish speaking people have two languages to speak in OR understand. Many customers may appreciate that you have some ability to recognize their language. You can also understand what any employees may be saying in Spanish, although many employers do not tip them off to understanding unless it is necessary. With only one language you can only hear part of what is said or meant, while a person with two languages has a big leg up on you from a selling or supervising/management standpoint.
It is not expensive to learn conversational languages. There are great cheap programs that allow you to listen and talk to an interactive program (usually less than $100 per language including headphones/microphone that also work for listening to music). You go it alone at your pace, so if you are not motivated, you can drag it out. You hear the language, find out what it means and then try it yourself. No memorizing (really). I have found that doing it for 15 minutes every day or two makes it easier than going heavy one day a week and forgetting about what you absorbed from a week ago. You also will get some very familiar words that quickly stick in your mind and even make it easy to wade through. Rosetta stone is good and you can get deals on it. I used Transparent Russian, Transparent Chinese, Transparent German and Transparent Spanish. I am nor fluent in any of those, but I could get by and find a toilet, but I did have a better idea of what was going on.
I traveled in 37 countries and found it very valuable to know (closely) what the locals were saying in their language. Often it is used instead of whispering in English (or American). I only tried to speak the language when absolutely necessary, unless I knew the people that I was with quite well.
India is not a problem, since most people speak English (not American), so it take a while to get comfortable. The official language in Hindi, but very often speak people do not speak that, so they got to the Queen's English.
It is always entertaining to visit a job site and have an idea of what everyone was saying in their language.
India is not a problem, since most people speak English (not American), so it take a while to get comfortable. The official language in Hindi, but very often speak people do not speak that, so they got to the Queen's English.