The Curtiss-Yamada Comprehensive Language Evaluation (CYCLE) is an in-depth assessment test that allows the clinician or researcher to examine comprehensively, a subject’s linguistic knowledge and performance in syntax, morphology, and semantics, and submodules in these components.

The CYCLE covers structures and features that emerge between 1 1/2 and 10 years of age, the active language development years. It includes a wide range of linguistic structures, including early to late acquired forms and grammatically simple to grammatically complex forms. The structures covered thus comprise a major part of the grammatical core of English. The CYCLE is useful for assessing whether specific aspects of the grammar are intact or affected and can be used with subjects across a wide range of ages and cognitive abilities.