Aspect is a general linguistic term utilised in the grammatical description of verbs; specifically, it is concerned with 'the way the grammar marks the duration of type of temporal activity denoted by the verb' (Crystal, 1991: 27). Originally used by specialists concerned with Slavic languages, in which aspect plays a key role, the concept of aspect has been shown to have significant implications for many other languages. In this article, the use of aspect and of aspectual markers in American Sign Language (ASL) will be explored. The argument to be presented is that ASL employs a variety of morphologically complex forms to express indications of aspect. For example, repetition and reduplication, changes in the direction of movement, changes in the nature of movement, changes in the speed of movement, changes in the use of space and spatial relations, as well as phonological changes, especially with respect to the use of a hold, all function to indicate aspectual distinctions in ASL. The morphological system for demonstrating aspectual relations will be explored, and implications for understanding aspect in the context of sign language linguistics will be discussed. Finally, comparisons will be made to similar phenomena in both British Sign Language and South African Sign Language. [ABSTRACT FROM AUTHOR]