Linguistics takes a descriptive approach to language: it tries to explain things as they actually are, not as we wish them to be. When we study language descriptively, we try to find the unconscious rules that people follow when they say things like sentence (1).

Is linguistic descriptive?

All academic research in linguistics is descriptive; like all other scientific disciplines, it seeks to describe reality, without the bias of preconceived ideas about how it ought to be.

Why is linguistics descriptive rather than prescriptive?

A descriptive grammar is a study of a language, its structure, and its rules as they are used in daily life by its speakers from all walks of life, including standard and nonstandard varieties. A prescriptive grammar, on the other hand, specifies how a language and its grammar rules should be used.