system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How is it possible to teach a person who is blind and deaf?
gpt
I'll stick your hand in water, and sign the word "water" into your hand. You'll eventually associate it. That is basically how it works. You slowly build up. You are presented something, and you are given the sign for it. Very similarly to how we learn to speak- we are presented something and given the word for it. Eventually, it advances into writing. 
 
While it is more difficult and not as extensive, it (obviously) can and has been done.