Head Movement and Adjacency

Considerable importance has been attributed to the problem of restricting the theory, but nevertheless certain options that generative transformational grammar provides have remained largely untouched. In the present article, one such issue is broached, viz., that of the choice between substitution and adjunction. The obvious solution of eliminating one of the two options is rejected on empirical grounds, but for the subdomain of head movement it is possible to formulate a theory which will decide whether a particular instance of head movement is a case of adjunction or of substitution. The crucial factor will be seen to be 'adjacency'. The Head Adjacency Principle (HAP) in effect says that any instance of head movement which does not take place under adjacency must be a case of substitution. Evidence for this proposal is presented from a variety of languages and constructions, with particular emphasis on the analysis of the contraction between prepositions and articles, analyzed as D-to-P Raising, in German.