If you could instantly learn a language, which one would you pick?

What about some important extinct language, so you can become world expert on it and be constantly praised as genius by everyone in the field? :<

I would learn Swedish or French, I think

German :3

Already know English so picking the language which would give me access to the greatest amount of things I am in interested in: Japanese.

Latin and Greek, then French and German. Mostly to read primary sources.

Japanese because that writing is hard as fuck

Chinese.

I'd pick Japanese because I'm a filthy weeaboo but I have more chance of learning that on my own considering Chinese is considerably harder.

German, for practical reasons. Been living in Germany for the past two years and my German is still embarrassingly awful :S

I would like to finish my Japanese studies, but I'll hardly have time and energy for it. Also would like to speak Dutch and Elvish

Russian because it sounds like a pretty kicka** language! I'm from Germany so I speak German fluently. My English is also pretty good and I had Latin, Japanese and Spanish already at school/university.

Japanese. I wish to met some Japanese girl.)

If it was instant and easy, it would be something like Latin, or some near obsolete language. Something I would never be able to, or be patient enough to learn otherwise.

I choose japanese, but also I'd like to learn sign langage ;)
I tried to but it's not easy ;)

Latin!

not shocked that Japanese is in the lead by a landfall!

Japanese because it's cool and because most of the products I use like videogames and mangas are from there.

American Sign Language. I live in one of the Deafest cities in the world, and not only are there just so many people here that I can't generally communicate with, it's a valuable job skill here.

After that I'd say French. Trying to do genealogical research on the Quebecois side of my family gets frustrating when so many of the marriage/baptismal records are handwritten in French. I can't begin to guess what the words are (yay, cursive!) and the Mormon volunteers who tend to be the ones transcribing the records are even worse at this stuff than I am. Plus there's all those great films.

I'd love to speak Turkish :C

I would learn Russian if only because Lenin spoke it.

Russian because сука

Japanese.. Because almost most of their top notch games never been release outside of japan in English.
Unless if one day somehow all of the Japanese game are now translated into English thanks to a publisher or something.

Chinese, given the amount of people that speaks said language (and given I'd be very used to writing in kanjis it'd be easier to learn japanese afterwards)

French, my wife speaks and teaches French. It would be nice to be able to converse with her. (edit: in another language)