If you woke up tomorrow with the ability to speak ANY foreign language that you do not currently speak, but you’d lose the ability to speak

You have a typo. I cannot even look at that question.  

depends on what language it was

I only speak one language fluently.  English, American style.  I'm sorry, in advance, if there are any typos in my answer.  I'm not as quick to catch them or grammar as you.
I did take a year of French in high school.  Unfortunately, I cheated through most of it. 
I do speak broken Spanglish.  Grrrrr.  This is only because of my geographic location.
I do speak and express body language.  I wouldn't change that one for the world or universe.
If I could speak any other language besides those, it would be Tibetian or Hindu.
I would love to learn more about that culture and means of thought.  To be able to speak it and read it, let alone feel and practice would be awesome.

There are so many languages in India itself, and most are "foreign" enough to me. I'd love to be able to speak Tamil fluently, a language my father speaks only a smattering of though his roots lay in south India, so I can teach him his own language. He has become too Gujaratified as he is third generation south Indian living in Gujarat, and married to a lovely Gujarati woman. On His father's insistence the family spoke Gujarati at home so they would assimilate well with the local community. 

No deal, Lucille.