The syntax of pro-drop in Thai

Abstract

Thai is a discourse pro-drop language (also called "radical pro-drop" language), since it exhibits highly frequent use of null pronouns without the involvement of agreement morphology. The descriptive goal of this thesis is to describe the different syntactic contexts in Thai where null pronouns occur and where they do not occur. The theoretical goal is to explain why pronouns sometimes have to be pronounced, sometimes may, but need not be, and sometimes cannot be pronounced, in Thai, and how this relates to pro-drop as found in other languages. The thesis will thereby hopefully contribute to the theory of pronouns, pronominal reference, and pro-drop. After an introduction (Chapter 1), the distribution of null/overt pronouns and the restrictions on their occurrences are discussed (Chapter 2). It is demonstrated that even though a null pronoun can appear in any argument position, it cannot take the position of a prepositional complement or occur in a conjoined NPs construction. It is also demonstrated that a null pronoun/argument in Thai always looks for an antecedent for a referential reading (Chapter 5). If there is no controlling linguistic antecedent for a null pronoun in a higher clause, then a discourse topic will be the antecedent. If there is no discourse topic either, the speaker is always available as a local antecedent of the null pronoun. The default referential reading of a null pronoun is therefore first person singular. It appears that this generalisation holds true in other discourse pro-drop languages as well (Chapter 3). Correspondingly, a pronoun without an antecedent must be overt. Pronouns with a generic or arbitrary reading are a special case of antecedentless pronouns, which can be null but only when they have generic inclusive reading (Chapter 4). I propose that null pronouns in Thai, and discourse pro-drop languages generally, have no ϕ-features, except for an unvalued referential feature [uR] and a general nominal feature [N]. These features are sufficient for the pronoun to function as an argument, being assigned a θ-role. They are dependent on being bound or controlled by one of the following: (i) a locally c-commanding referential NP, (ii) a null topic operator, which itself is linked to a referential NP in the discourse, (iii) "the speaker", as default, (iv) a generic operator, or (v) a higher generic argument (Chapter 6). That an inclusive generic pronoun is not pronounced (as opposed to other generic/ arbitrary pronouns, which are pronounced) is explained by the presence of a generic operator. The operator behaves just as an adverb that quantifies over the null arguments, i.e. "It is generally true for x." The [uR] feature of the pronoun is probed by this generic operator. As the pronoun has no ϕ-features, it gets a referentially unrestricted reading. This is the inclusive reading of a null generic pronoun. It includes the speaker, the The Syntax of Pro-drop in Thai addressee, and any other people. In other words, the generality of the inclusive reading is from the ϕ-featureless pronoun, in which case it has no restricted reference. Since exclusive generic/arbitrary and quasi-inclusive generic pronouns have more restricted reference, i.e. third person plural and first person plural, respectively, they must be overt when bound by the generic operator. If they were null, they would be indistinguishable from the unrestricted inclusive generic pronoun and the referential first person pronoun "I", since they have no antecedent providing them with features. This means Thai can have relatively unrestricted use of referential third person/impersonal null subjects and a null inclusive generic subject pronoun. I show that this pattern is also found in other discourse pro-drop languages, and is restricted to languages where agreement is not part of sentential syntax. A null argument of the type [uR, N] in turn constitutes a new category in the typology of null arguments. It explains why it cannot function as a prepositional complement, which requires a complement with ϕ-features. This implies that referential null pronominal arguments do not inherit any ϕ-features from their antecedents. The only thing they inherit is the referential index. To summarise, null pronominal arguments do not have ϕ-features, and thus are not pronounced. Pronominal arguments with ϕ-features can be pronounced. In this, and in several other respects, null pronouns in Thai and other discourse pro-drop languages are similar to PRO in languages like English.