Linguistic research demonstrates, however, that ASL is comparable in complexity and expressiveness to spoken languages. It is not a form of English. It has its own distinct grammatical structure, which must be mastered in the same way as the grammar of any other language. ASL differs from spoken language in that it is visual rather than auditory and is composed of precise handshapes and movements. ASL is capable of conveying subtle, complex, and abstract ideas.
Signers can discuss philosophy, literature, politics, education, and sports.
Sign language can express poetry as poignantly as can any spoken language and can communicate humor, wit, and satire just as bitingly. As in other languages, new vocabulary items are constantly being introduced by the community in response to cultural and technological change. ASL is not universal. Just as hearing people in different countries speak different languages, so do Deaf people around the world sign different languages. Deaf people in Mexico use a different sign language from that used in the U.S. because of historical circumstances, contemporary ASL is more like French Sign Language than like British Sign Language.