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.

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.

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

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

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

Language

The study of meaning in language is known as semantics.

Syntax

Semantics

General linguistics is generally the study of language as a whole.