1. Introduction
Sentences marked with the morpheme bèi 被 in Mandarin are known as “bèi-sentences”, which are to some extent comparable to passive sentences in English. The morpheme bèi occurs before the agent NP, such as (1), where Lǐ Sì 李四 is the agent NP and Zhāng Sān 張三 is the patient NP. When the agent NP is absent, bèi precedes the verb, as in (2). In what follows, the former is referred to as a long bèi-sentence while the latter is referred to as a short bèi-s…