Sign language is not a spoken language. A joke was posted on AskReddit on July 9, 2020:
       
“I know several jokes in sign language. I guarantee nobody has ever heard them.”
     
       
Reddit—AskReddit
Posted by u/Evergreenn7 July 9, 2020
What is a go to joke you know nobody’s heard before?
COMMENTS
mynameisbirthdayboy
I know several jokes in sign language. I guarantee nobody has ever heard them.
 
Twitter
ʲᵒˢᵉ
@joseslittlemind
I know several jokes in sign language.I guarantee nobody has ever heard them.
2:57 AM · Jul 9, 2020·Twitter for iPhone
   
Twitter
KNG Hevra
@takemyhanose
Replying to @PlaIism
I know a few jokes in sign language to make u laugh. I guarantee no one ever heard them.
6:00 PM · Jul 11, 2020·Twitter for Android
   
Twitter
One Liners
@humurous1liners
I know several jokes in sign language. I guarantee nobody has ever heard them.
7:52 PM · Jul 13, 2020·SocialOomph
   
Reddit—Jokes
Posted by u/thaijahn September 2, 2020
I know several jokes in sign language
I guarantee nobody has ever heard them.
 
Twitter   
Dad Jokes
@Dadsaysjokes
I know several jokes in sign language.
I guarantee no one has ever heard them before.
4:13 PM · Sep 2, 2020·Twitter for iPhone
 
Reddit—Dadjokes
Posted by u/confused-avocado72 September 17, 2020
I know several jokes in sign language
I guarantee you,no one has ever heard them before.