We all need language to develop, but language doesn’t have to be verbal. For a deaf person, the language you think in would depend on when the deafness occurred. If it happens after a verbal language is learned, they will think in that. But those born deaf who learn sign language at a young age think in sign language too. This offers all the same tools as a spoken language – the ability to obtain/process knowledge, manipulate symbols and understand abstractions. It’s just based on gestures rather than words.
Answered by Shanna Freeman.