The theory of Generative Grammar proposes that every member of the human species is born with a language acquisition device (LAD), a faculty of the human brain which enables us to acquire a language naturally and easily, just as birds acquire their skill of flying. The process of acquisition operates according to two kinds of constraints or guidelines, namely principles and parameters. Principles are a set of constraints or features common to all languages, and are characteristic of the LAD per se. Parameters, on the other hand, are a set of features which have two possible polar values, and different languages make use of different combinations of values of these parameters. Hence, the different linguistic or syntactic structures in the many languages of the world arise from the use of different combinations of these parameters.
Of these parameters, one of the earlier and more studied is the Pro-Drop Parameter. Chomsky’s (1981) original discussion of the parameter only considered inflectional languages such as Italian and English, but the definition was later generalized to include all languages in which a structural NP can be omitted in the surface form if it can be deduced from the discourse. The most common form of pro-drop is subject pro-drop, or null subject, which can be seen in almost all pro-drop languages. Object pro-drop, or null object, is much less common, and is not found in typical subject pro-drop languages such as Italian and Spanish. It is, however, relatively common in Asian languages such as Chinese, Japanese and Thai.
Despite surface similarities, a number of asymmetries exist between null subject and null object. An immediate interesting question to ask is whether they belong to the same phenomenon and can be treated on a par. Huang (1984) suggests that while null subject is a true argument dropping process, null object is in fact a topic dropping process. In this paper, I am going to look closer into the distribution of null object, further verify this proposal and discuss several relevant issues.
Download (208.5 KB)