Modern linguistics is mostly prescriptive, but sometimes descriptive.

D（）is one of the design features of human language which refers to the phenomenon that language consists of two levels: a lower level of meaningless individual sounds and a higher level of meaningful units.

Language is p（）in that it makes possible the construction and interpretation of new signals by its users. In other words, they can produce and understand an infinitely large number of sentences which they have never heard before.

A diachronic study of language is the description of language at some point in time.

Syntax is different from morphology in that the former not only studies the morphemes, but also the combination of morphemes into words and words into sentences.

Morphology

Pragmatics

Semantics

A scientific study of language is based on what the linguist thinks.

In the study of linguistics, hypotheses formed should be based on language facts and checked against the observed facts.