Crosslinguistic influence (CLI) refers to the different ways in which one language can affect another within an individual speaker. It typically involves two languages that can affect one another in a bilingual speaker.[1] An example of CLI is the influence of Korean on a Korean native speaker who is learning Japanese or French. Less typically, it could also refer to an interaction between different dialects in the mind of a monolingual speaker. CLI can be observed across subsystems of languages including pragmatics, semantics, syntax, morphology, phonology, phonetics, and orthography.[2] Discussed further in this article are particular subcategories of CLI—transfer, attrition, the complementarity principle, and additional theories.