Let's gather some information on the linguistic capabilities of our researchers.
  
I am really interested to know who has deep native, acquired, or
scholarly command of languages other than English to the point of
being able to answer questions not just about individual words and
translations but also about the language itself, its structure,
patterns, and subtleties, its literature, and the culture that
pervades it.

Researchers, if you're willing, would you please identify yourselves
with respect to your native and acquired languages using the following
terms:

native command (NC) - the language is your mother tongue

high fluency (HF) - the language is an acquired second language that
you speak, read, and write with the next best thing to a native
command

academic proficiency (AP) - the language is your field of academic
study, or you have a high degree of formal learning in the language
(especially applicable to classical and dead languages)

I would like to be able to compile a list something like this:

<GA Researcher 1>
   German (NC)
   Latin (AP)
<GA Researcher 2>
   French (HF)
   Spanish (HF)
   Portuguese (HF)
<GA Researcher 3>
   Hindi (NC)
   Sanskrit (AP)

I regard each of the dimensions as a yes/no condition; that is, in my
estimation, if you have to qualify your degree of expertise, it isn't
the expertise I'm looking for.  If you have to say "moderate fluency"
or "somewhat proficient," then the label "high fluency" or "academic
proficiency" doesn't apply.

The result would be an alphabetical list by language that looks
something like this, where a researcher's name take the place of
"GARx":

French
  GAR3 (HF)
German
  GAR8 (NC, AP)
  GAR22 (NC)
Hindi
  GAR11 (NC)
Japanese
  GAR16 (HF, AP)
Latin
  GAR8 (AP)
Sanskrit
  GAR11 (AP)

The list is the answer to the question, but it will depend on
receiving some number of comments as data.  Let's say twenty comments
with data are enough to make a table and post an answer.  It would be
best if a researcher didn't lock the question until there is enough
data to compile a list with some scope to it.

Personally, I am most likely to be looking for answers pertaining to
these languages:  German, French, Japanese, Latin, Greek, Sanskrit. 
But you never know.  Sometimes I have a burning question about
Afrikaans or Finno-Ugric, and it would be nice to know where there is
expertise.
 
Thank you,
Apteryx

NC -- Amurican
HF -- French
LF -- Swahili

Best regards,

Omnivorous-GA

Is Sanskrit really a language?

I always thought it was a detergent.

American English (NC)
Dansk (HF)
Espaņol (AP) 

---larre

Bryan,

Absolutely.  Samskrta is a supremely cool and amazing language.  The
more I learn about it, the more I am impressed by its sheer
awesomeness.  If I had those twelve other lifetimes for all the things
I'd like to do, one of them would be given to a deep study of this
most polished and perfected language.

Namaste,
Apteryx

From your list I know only some German (and a little English). 

I also know (AL) Hebrew, Armaic and Arabic. 

I have abilities in Scadinavian (as in *not* Finnish) languages and in Russian.

Politicalguru,

Thanks.  My list was only an example and by no means exhaustive.  I'm
interested in linguistic expertise in *any* language.  Speaking just
for myself, I am likely to want to ask some questions just based on
knowing a particular researcher's combination of languages.

Apteryx

I would love to be able to reel off a list of languages in which I am
fluent (or even academically proficient), but, in all honesty, English
is the only language I have mastered. Or mistressed.

I am a language-dabbler, and have acquired bits and pieces of many
languages. I read and write French and Spanish rather well, but have
difficulty with the spoken language. I have gathered smatterings of
German and Italian. I have small Latin and less Greek.

Turkish (NC)
English (HF)

Hungarian (NC)
American English (HF)

I'm also fairly proficient in German and have some knowledge of Latin.

~ czh ~

Well, my native language is German. I'm fluent in English (though I
sometimes make some of the mistakes typical for Germans), and I have
learned French for five years. I can read basic Dutch, but I can't
speak or write it, and following a Dutch conversation is a tough
challenge for me. And I can understand spoken Low German, but
unfortunately I lack the talent for speaking it myself. And I know
some bits of Latin, as a result of my interest in history.

Greetings,
Scriptor

Interesting question! It's fun to see what everyone posts! Well, I'm
100% Portuguese (born and raised in the U.S.) and grew up speaking
both Portuguese and English. Technically, I grew up speaking
Portuguese first and over time my English improved so much so that I
speak English better than Portuguese, though I am quite fluent in
Portuguese (HF). Of course, when I am around extended family (where
speaking is loud, lively, fast, and accompanied by lots of hand
motions!), I feel more and more comfortable with my Portuguese. I also
speak Criolo (Portuguese Creole--spoken in Cape Verde, West Africa) .
. . picked that up while living there for 7 months. Now, THAT'S a fun
language! And since Spanish is pretty similar to Portuguese, I can get
by quite well with that, too.

Sinceramente,
Boquinha-ga

Tagalog (NC)
English (HF)

I'd like to learn French, German, and Spanish if only I have extra
money for these. Language courses are expensive here in my place.

"Is Sanskrit really a language? I always thought it was a detergent."

When I was a kid I thought it was an orange. :D

Sumasainyo,
Feilong

NC -- Spanish
HF -- English

Regards.
livioflores-ga

Very impressive!

And another Great Question.

But very humbling ...

Me? I can only manage a few words of Oklahomaese, like Howdy-hi.

English - NC
Spanish - HF

Ciao, crabcakes

English - (NC)
Spanish - (HF)
I can read and write in Hebrew and I know some French.

Best regards,
Bobbie7

NC - Russian
HF - O'Odham
   - French
   - English
   - Spanish
AP - Italian
   - Latin

And a few others I picked up during schooling in Europe, which was a
few decades ago.

~ Serenata

Tagalog (NC)
English (HF)

It looks like Serenata gets the prize.
I needed Google just to identify O'Odham

-R
[english and high school french, sad to say....]

Although I'm Filipino, here's an irony:

English (NC)
Filipino (HF)

This question runs only for a couple of days, but several common
languages are significantly missing:
- Chinese (though I know of at least two GARs who could Research in
Chinese, and in fact also did it on GA)
- Hindi; Bengali
- Indonesian, Malaysian
- Korean
- Farsi
- Greek (ancient and modern)

I would have also expected more GARs to have AP of Latin, and at least
that has NC of Arabic or French. We also have a deficit in Slavic
languages: Russian (NC) by Serenata? That's all? What about Bulgarian,
Serbo/Croat, Polish, Czech, etc.?

And - could any of us speak Esperanto?

NC -- American English
LF -- French

Excellent results so far!  Thank you!  This is not a contest, but
Serenata does have an impressive list.  I have a feeling that there is
a story behind someone's having a native command of Russian and
achieving high fluency in a language of a native people of the
American Southwest.  Serenata, could you please tell us how to
pronounce the word "O'Odham"?

Like Politicalguru, I am hoping to see more representation of the
Asian languages (including Japanese), and a broader spectrum of
European languages, too, from Greek to Icelandic.  And let's not
forget the many African languages...and Hawaiian and Inuit...and all
the others.  And Sanskrit!  I would expect to find some of almost
everything on GA.

Apteryx

I was delighted to discover that, like me, the talented Serenata can speak O'Odham.

But I wonder, is she really as fluent as me?

For the record, I was born in Oldham, Lancashire (in the UK) which is
famous for its 'Owdham' accent so, as a native, I believe that I
probably have the edge.

Bryan, 

Now you can learn how to talk in other languages: 

Ten Lancashire expressions translated into European languages... 
<http://www.bbc.co.uk/lancashire/fun_stuff/lists/languages.shtml>

Omigod, Politicalguru

Now, I know why I am daft.

English (NC)
Legalese (HF)

czech  NC 
 
english (US)  HF

Brooklynese (NC)

Native speaker of American English, reasonable proficiency in Spanish.

English plus enough Farsi to ask directions and order dinner, the same with Arabic.

Hi Apteryx,

Great question...

Serenata...holy crap!

English - (NC) grammar don't count do it?
Vulgarities - (NC)
Pig Latin - (HF)
SQL - (HF)

I grew up in a house with an italian Grandmother, and great
Grandmother. Gram spoke Italian and english and Nonna spoke English,
Italian (several dialects), French, Spanish and some German. Mostly
curses, in that house I knew how much trouble I was in by counting the
languages in the stream of curses coming at me. I have no written
skills as far as being proficient, but I can speak and understand
Italian and Spanish.

Hope this helps, I may have padded my list so I don't look like the
slow kid in the class.
Mother911-ga

Though I am not a GA Researcher, I feel the need to add my own
proficiencies to the list...

English (NC)
Hungarian (NC)
Spanish (AP)

Learned Hungarian first, though my English is now better.  Studied
Spanish for 5 years in middle/high school, 5 semesters in college.

English (NC)
Japanese (HF)

English (NC)
Japanese (AP)

I'm hoping to improve my Japanese to HF, but it'll be a while. In the
meantime, I get by well enough with speaking, reading, and writing,
and it is my field of study, so I went with AP. :)

Hi

NC Afrikaans
HF English

I'm interested to know what you would like to know about Afrikaans?
regards
tabas

Afrikaans?

That's just Dutch spoken with a funny accent, is it not?

Arabic (NC)
English (HF)

I'm glad people are continuing to answer this!

Tabas, I do not have a question about Afrikaans.  It was an example. 
I asked about languages in case of future need.  Thank you for
responding.

Archae0pteryx
(formerly known as Apteryx)

Hebrew (Modern & Ancient) - NC
English (Modern) - HF
Arabic - AP

Spanish (NC)
English (HF)
French (HF)
Some bits of Latin I remember from highschool.
As any native Spanish speaker, I can manage pretty well with Italian
and Portuguese, specially written, or talked at a low speed.