- Null Subjects, Switch-Reference, and Serialization in Jabêm and Numbami
Analysis of null vs. overt subject NPs over successive clauses in texts from Numbami and Jabêm, two Austronesian languages of Papua New Guinea with rich subject-agreement morphology and rich verb serialization, reveals that optional null subjects normally signal subject retention across clauses while optional overt subjects signal switches. Comparison of these discourse-level switch-reference systems with clause-level verb serialization in the same languages, and with morphological switch-reference systems in neighboring Papuan languages and distant Austronesian languages reveals considerable functional overlap between canonical switch-reference systems and canonical verb-serialization systems, but with null subject NPs signaling similar types of continuity in both systems. Optional null subjecthood marks not just subject continuity across successive clauses at the discourse level, but also actor continuity, just as obligatory null subjecthood on noninitial verbs marks continuity of actors, patients, and other thematic roles across successive serialized verbs at the clause level.
This study examines the occurrences of null vs. overt initial subject NPs in successive clauses in texts from Jabêm and Numbami, two Austronesian languages of Morobe Province, Papua New Guinea. Both languages are SVO and have rich and uniform systems of prefixes that uniquely identify the person and number of the subject of each verb. Null subjects in clause-initial position are thus very common and normally signal retention of the subject (and actor) of the prior clause, while overt subject NPs signal a switch in clausal subject (and actor). That much is fairly easy to demonstrate, but the analysis is complicated by two intersecting phenomena.
(1) Both languages are especially rich in serial verb constructions (SVCs) that allow SVC-internal subject-agreement switches between successive verbs. Like other clause types, Numbami and Jabêm SVCs allow subject NPs to be either overt or null in initial position, but allow no other overt subjects anywhere else in the same clause. Each succeeding verb in an SVC can introduce a new thematic [End Page 270] role (patient, goal, location) in object NP position, but it cannot place a competing entity in a role already assigned earlier in the clause. Thus, a null-subject sequence such as 'we-carry taro we-carry bananas' (with pronominal prefixes here signaling subject agreement) cannot be analyzed as a single SVC-despite actor continuity- because it contains two competing patients ('taro' and 'bananas'). The same goes for 'we-carry food we-go inland we-go seaward', because it contains two competing goals-of-motion. But 'we-carry food we-go we-put it-lie house-inside' is a fine SVC because the whole sequence shows continuity of actor ('we'), patient ('food'), and location ('house-inside')-as well as continuity of tense, polarity, illocutionary force, and so forth.
(2) Both Numbami and Jabêm have long been in contact with Papuan languages that have canonical switch-reference (SR) systems that morphologically mark subject continuity (ss) and discontinuity (ds) in the medial verbs of clause chains. Such clause chains may sometimes show levels of cohesion that approximate those of SVCs. In fact, some SVCs and clause chains are close translation equivalents. Attention is thus devoted to sorting out the differences among tracking subject relationships within SVCs, within SR clause chains, and within stretches of independent clauses.1
1.1 Data Sources.
Jabêm (sometimes spelt Yabem or Yabim) is already among the best-recorded languages in Melanesia. Dempwolff (1939) undertook a grammatical description as his last publication. Zahn (1940) provides a thorough pedagogical grammar, with abundant exemplification. Zahn earlier produced a (1917) Jabêm-German dictionary, and Streicher has produced both a (1937) German-Jabêm dictionary and a (1982) Jabêm-English dictionary. Since Jabêm was a church and mission-school lingua franca used since the turn of the century throughout Austronesian-speaking areas of Morobe Province, there are also abundant materials in the language: primers, texts about a variety of traditional and modern customs and scientific beliefs, historical accounts of World War II, traditional and biblical tales, hymnals and liturgy, the entire New Testament and most of the Old Testament (Streicher 1982:657-658). The Jab...