american sign language
after the new language tools come out will it be possible to do asl ( american sign language )
Knowing the alphabet in sign language (which you can easily find on many other sites) is only a small step. While technically you can spell a word out and be understood, could you imagine having a conversation where you had to spell every single word? Think about how long that would take and how much effort would be required to watch a string of letters and then convert it into a meaningful word in your head. If you truly want to communicate, you need to learn the vocabulary just like any other language.
Grammar and sentence structures in ASL are also very different than spoken English. Many words are condensed and omitted. While you can be understood using spoken English sentence structures, it takes a lot longer to communicate that way and may be confusing at times. To show the contrast:
Spoken English: I am going to the store. Would you like to go?
ASL: I store go you?
ASL is flexible, so it could be signed differently (adding details or different structure), but that's just an example.
I know ASL and it's incredibly hard to learn from pictures. Most signs involve movement, which is very hard to convey with a 2 dimensional still picture. Most ASL books provide a description to help you understand, which helps with most signs. But even with that I've had a few signs that I learned incorrectly or still couldn't figure out and had to get help from a deaf person.
It would be possible with videos, but obviously Duolingo is not set up to do that right now. Even if it was set up for videos, it would be time intensive for people to record all of the videos for each sentence and variation. That takes a lot longer than someone typing sentences in another language. It also requires experts that are willing to show themselves on video to the world. Plus, there would be no way for you to sign something and have Duolingo verify that what you did was right or not.
There are lots of resources out there if you want to learn sign language. You will make better progress if you can connect with deaf people (which are usually very patient with people trying to learn). But it's not a language I expect to see on Duolingo soon (but maybe in the more distant future).
I would modify that statement to say "ASL does not have a commonly-used written component." There is the problem of trying to input ASL into a machine reader to codify into an online version. The closest system that I have seen that could be used in keyboard inputs and/or text-tracer inputs would be the system found at http://www.si5s.org/
People have mentioned that it would be difficult to learn ASL from still images. That is likely true, but if a large collection of videos featuring signs (like those in the ASL dictionary used for SMARTsign --check out: http://www.cats.gatech.edu/content/smartsign) were incorporated, this functionality might be possible.