Abstract It has been commonly assumed that syntax can exert influence on prosody, but itis much less widely recognized that
prosody can also constrain syntax. In this paper, I will support the second claim with data from Chinese and argued, first, that the so called sentential normal stress in Chinese is assigned through the last main verb within the lowest VP domain. Second, I will argue that this pattern of stress assignment interacts directly with syntactic structures of
sentences formed by a head with its complement/s, hence any violation of the
prosodic principle will results in an ungrammatical output even though the sentence is syntactically well formed. The paper starts with a general observation on factors determining the grammaticality of
sentences, and then illustrates how the normal stress is assigned in Chinese and how the prosodic constraint rules out ill formed sentences such as (i) Bare verbs in the Ba constructions, (ii) prosodically heavy objects in sentences and (iii) the structures. Finally, it claims that if prosodic structure is considered as an independent level of grammar, the grammaticality of the sentences discussed in this paper can automatically be derived from an interaction between rules or constraints of different levels of the grammar.