“Languages have a structure which is commonly referred to as grammar. This implies that language is a rule governed system. It also means that words in sentences have a relationship. Furthermore, in most languages words have a fixed order in a sentence. The assumption of an underlying structure makes it plausible that all natural languages share common features. The surface structure of languages is derived from the underlying basic order through movement procedures. The lexical categories (i.e. words) in a sentence undergo changes (e.g. verbs are inflected). The changes that form to say a shell around the lexical entities are called functional categories. Functional categories are syntactic operations, that do not refer to entities in the real world. It is assumed that these categories are more difficult to acquire.”
From: Going the distance: A Non-Linear Approach To Change In Language Development. H.G. Ruhland. Groningen, 1998.
© Rick Ruhland 2018