a couple of random things i came across about sign language while playing a deaf character:
- british and american sign languages are NOT mutually intelligible
- lots of / flashy jewellery can make signing difficult to follow
- deaf people who grow up without someone to teach them signing and where writing is impractical can end up essentially isolated in their own minds
- lots of things don't actually have a specific word in sign language and are instead fingerspelled
- it's not uncommon for signs requiring two free hands to be adapted to use just one if the person is holding something at the time
- puns in sign language are absolutely a thing, e.g pasteurised milk, the word 'understand', etc