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.

Pragmatics is different from semantics in that pragmatics studies meaning not in isolation, but in context.

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

The distinction between competence and performance was proposed by F. de Saussure.

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.

Modern linguistics is different from traditional grammar.

P （）refers to the realization of langue in actual use.

Morphology

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

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