Referential accessibility as an index of the discourse functions of predicative and specificational clauses.

This paper studies referential accessibility marking in predicative and specificational clauses, in particular the ones in which the roles of 'description' and 'variable' are realised by an indefinite NP (e.g. He is a baker vs. One of his talents is pastry). While the indefinite NP in the two clause types has been studied in detail, little is known about how the other two roles – of 'describee' and 'value' – are typically realised. This study, therefore, examines the choice of referring expressions for the items filling these roles, as an index of their retrievability and degree of accessibility. The analysis is based on 750 corpus examples from spoken and written British English. Moreover, since specificational clauses allow for the value to be either complement or subject, this study also provides insight into what may motivate the choice for one pattern or the other. Significant differences were found between describees and values, as well as between value-subjects and value-complements. These findings are interpreted as indicative of different discourse functions of the three constructions. While predicative clauses typically elaborate familiar information, specificational clauses serve a broader discourse-organising function: starting a new discourse-topic, pivoting from one topic to another, or summarising prior propositions as concluding a topic. [ABSTRACT FROM AUTHOR]