The fundamentals

From the bottom-up perspective discussed in the previous chapter, the creation of phrase structure representations consists of two procedures, grouping and labeling:

(i)concatenate two (or possibly more) syntactic elements into a single syntactic object, a phrase;

(ii)label the phrase created, using the category label of one of the syntactic elements in the phrase constructed by (i).

(i) and (ii) together constitute a single syntactic operation called Merge. The steps by which the phrase structure of a linguistic expression is constructed is called its derivation. Each derivation will therefore involve several successive applications of Merge to the lexical items contained in the expression and to the syntactic objects constructed by the previous applications of Merge. In this way, Merge re-applies to its own output and is therefore a recursive procedure, thereby providing the grammatical mechanism by which the computational system of human language (CHL) can produce arbitrarily long sentences. That is, in principle there is no limit to the number of times Merge can apply in the derivation of a sentence, thereby yielding infinite use of finite means: the single recursive procedure Merge applied to the finite lexicon.