American Sign Language (ASL) classifiers show where someone or something is moving, where it is, and its appearance (e.g., size and shape). In sign language, an ASL classifier serves the same purpose as a pronoun in English. First, the word must be used, then the ASL classifier can be used to represent the word.
There are many ASL classifiers, involving handshapes that represent numbers and letters. Classifiers are referred to as "CL" followed by the classifier, such as, "CL:F." One set of classifiers is the use of the numbers one to five. Another set of classifiers uses the letters and letter combinations A, B, C, F, G, ILY(Y), L, O, S, U, and V. As an example, the "1" ASL classifier can represent people walking. In another example, the "A" classifier can represent a house.
ASL classifiers are an important part of learning sign language, especially for people learning to become interpreters for the deaf and hard of hearing. Students learning sign language often post their ASL classifier assignments on YouTube.
The Journal of Deaf Studies and Deaf Education has published several articles related to ASL classifiers. In one example, in the article "The Acquisition of Spatial Constructions in American Sign Language and English," researchers examined the learning of spatial relationships such as the concept of "front." The study involved both children and adults, both English users and ASL users, and subjects were tested with pictures and sign language (for ASL users).
Study results showed that children learn concepts like above and below quick because there is no perspective shift involved (i.e., there is no need to picture mentally the actual location). However, concepts like "front" and "behind" take longer to learn because they do involve perspective shifts. This was found to be true for both ASL and English users but it took longer for ASL users. According to the study's authors, this may be because of how difficult it is for young children to acquire mental perspectives (called rotations). In addition, young deaf children in the study understood relations with people classifiers better than with animal or vehicle classifiers.