Language proficiency

Language proficiency or linguistic proficiency is the ability of an individual to speak or perform in an acquired language. As theories among pedagogues as to what constitutes proficiency go, there is little consistency as to how different organizations classify it. Additionally, fluency and language competence are generally recognized as being related, but separate controversial subjects. In predominant frameworks in the United States, proficient speakers demonstrate both accuracy and fluency, and use a variety of discourse strategies. Thus, native speakers of a language can be fluent without being considered proficient. Native-level fluency is estimated to be between 20,000–40,000 words, but basic conversational fluency might only require as little as 3,000 words.

The American Council on the Teaching of Foreign Languages (ACTFL) distinguishes between proficiency and performance. In part, ACTFL's definition of proficiency is derived from mandates issued by the U.S. government, declaring that a limited English proficient student is one who comes from a non-English background and "who has sufficient difficulty speaking, reading, writing, or understanding the English language and whose difficulties may deny such an individual the opportunity to learn successfully in classrooms where the language of instruction is English or to participate fully in our society."

ACTFL views "performance" as being the combined effect of all three modes of communication: interpretive, interpersonal, and presentational.

Note that test scores may not correlate reliably, as different understandings of proficiency lead to different types of assessment: