American Sign Language (ASL) uses hand shapes, positions, movements, body movements, gestures, and facial expressions as its primary means of communication, unlike spoken languages which rely on sounds and intonation. While its exact origins are unclear, ASL likely developed from French Sign Language which was introduced to America in 1817, merging with existing forms of sign language used by deaf Americans. ASL is a complete, complex language and is considered the primary language for many deaf North Americans. Research shows that acquiring ASL at an early age, before school, is important for fully developing competence in the language.