On The Syntax Of The English Pro-form Do So

The expression do so is fairly widely used in English, but has received relatively little treatment in the literature. This paper explores the internal syntactic structure of do so, and what its internal structure says about the structure of VPs in general.In the literature of generative linguistics, there are three main different accounts of do so. In the phrasal pro-form analysis, do so as a whole unit is treated as a phrasal expression that replaces a VP structure; as a phrasal verbal pro-form, do so typically targets Ⅴ-bar (Ⅴ’) constituent. One obvious problem with such an account is that it says nothing about the internal syntactic structure of do so. According to the light verb analysis, the do in the do so construction is an instantiation of light verb v, while so is the pro-form for the lexical VP. Under the anaphora analysis, do so as a whole unit is argued to be a deep anaphor; as a deep anaphor, do so does not replace any structure in the verb phrase, but rather forms a verb phrase in its own right from the beginning of the derivation, and therefore the use of do so is not a reliable test for the internal structure of the verb phrase.After a detailed review of the above-mentioned accounts, this thesis argues that the light verb analysis of do so is basically on the right track. It is shown that the do of do so is not dummy auxiliary do or main verb do, but rather a light verb v. As a light verb, do in do so is an overt reflex of a functional head that licenses the external argument in eventive VPs. This head combines with a constituent containing the verb and its internal arguments and contributes an external argument to it. Do and so are merged as distinct heads. So serves as the VP-pro-form complement of do, replacing a constituent which includes the lexical verb and its dependents but excludes the external argument and do, suggesting that the external argument is dependent of do, not of the lexical verb.The fact that both transitive verbs and intransitive verbs (including unergatives and unaccusatives) can be replaced by do so strongly suggests a more generalized light verb projection, in which do or its covert counterpart functions as a general light verb v, with transitive or intransitive, unergative or unaccusative properties, and therefore this general v is in fact compatible with all types of lexical VP complements. In this respect, so truly resembles a pronoun and it replaces a lexical VP constituent.