According to the "principles-and-parameters" theory, "principles" refer to highly abstract properties of grammar which are applied to language in general and which generate phrases and at the same time restrain the power of Move a, while "parameters" allow general principles to operate in certain restricted ways, according to which particular grammars of natural languages vary.

Well-arranged sentences are considered grammatical sentences that are formed following a set of syntactic rules.

A compound is the combination of only two words.

In classifying the English consonants and vowels, the same criteria can be applied.

Linguists can concentrate on all the aspects of language at once.

附加应力指建筑物荷载通过基础传给地基在接触面上的应力。

土的质量密度与土的比重为同一概念。

当土中孔隙完全被气体充填时，称为饱和土。

随深度增加，土的附加应力越来越大。

当土中孔隙完全被水充填时，称为饱和土。