Forms and Functions of Copulas: A Study on Nominal Predicate Sentences

Theories on the functions of copulas normally include Linker Hypothesis, Dummy Hypothesis and Predicator Hypothesis, all of which have their limitations, especially when applied to Chinese.In a cross-linguistic perspective, the present paper describes the copulas synchronically and diachronically, revealing that the functions of copulas are to indicate or emphasize the interpretation of “topic-comment”, i.e.predicate-indicator.Copulas are obligatory in more grammaticalized languages (such as English), and thus they are called grammatical copulas.In less grammaticalized languages (such as Chinese), the interpretation of “topic-comment” relation resorts to context and world knowledge.Copulas in these languages are optional and are thus called pragmatic copulas.