Spanish

I took five years of Spanish and use it regularly... but I don't make any more money for it. I'm not sure how one would "make more money" just for knowing Spanish, unless one took a medical interpreter course and worked as one during school or on a per diem basis.

Check your local community college. I live in an are with a large Hispanic population, and the community college is able to meet the need by offering Spanish as well as a Spanish of Healthdare Professionals.

As far as using to make more money, you might be able to if you employer allows employees to offer translation services, which often comes after proving competency and taking a short class on how to translate.

Agree with PP - fluency in additional languages may give you an advantage when it comes to obtaining a job, but I wouldn't expect it to raise your salary.

I don't know of many hospitals that are utilizing clinical staff as medical interpreters... there is too much difficulty getting them free from their regular assignment to perform interpretation services & conflicts of interest can be a problem. Generally, if they have in-house interpreters (certified) they 'live' in HIT (used to be medical records), admitting, or patient advocacy/relations departments.

Speaking another language helps you get hired, it doesn't get you more money. Looks good on a resume, and is a good thing to have as a tool when non-english speaking patients and family are around.
I've found rosetta stone to be helpful.

I agree with the PP. Being bilingual will make you more marketable as a nurse but won't necessarily get you more money. Most employers stopped the extra benefit pay of being bilingual years ago.

I doubt that they would ask you how you learned it. They'll just want to make sure you aren't lying about being fluent in it. I wouldn't put it on a resume until you reach a high intermediate level and able to carry on conversations without long pauses.