Since linguistics is the quasi-scientific study of language, and theory in linguistics is developed after language is developed, linguistics makes us consciously aware of our implicitly acquired language skills. Linguistic theory makes us aware of our tacitly acquired language skills through a system of concepts and rules. Additionally, linguistics is not prescriptive , establishing rules that users should follow, but descriptive , merely establishing what occurs in the use of language. Knowing how to use language without reference to explicit concepts and rules is known as grammatical competence. Since it is implicit knowledge, competence allows one to produce and understand language in a fluent and unreflective manner.
Most people acquire grammatical competence by school age.
On the other hand, the ability to actually produce or comprehend language is known as performance . An individual may know how to write a good essay, for example, but producing a good essay may be difficult for them. Performance requires the coordination of more variables than competence. In order to improve student performance, the doing of language, I keep a writing folder for each student. Periodically, students participate in a writing assignment, usually an essay.