本文以表否定道義模態意的「V 什麼NP」為研究對象，從NP 複雜度對該結構合法與否所產生的影響出發來考察焦點重音與核心重音之交互作用。我們提出該結構中的「什麼」是一個低位焦點詞，它區別於以「別、不要、不、只」為代表的高位焦點詞。低位焦點詞帶弱焦點重音，高位焦點詞帶強焦點重音。低位焦點重音對核心重音的抑制作用較弱，需與承載核心重音的NP 一起重新分析，從而對NP 複雜度產生限制；高位焦點重音較強，可直接抑制核心重音，無需與NP 重新分析。此外，我們探討作用於語音層面的對比焦點重音對高、低位焦點重音及核心重音的抑制作用及可能的解脫機制。

This paper studies grammaticality variation with the size of NPs in the Mandarin ‘V shenme NP’ construction with negative deontic meaning from the syntax-prosody interface. We investigate the interactions between different types of stresses and propose the following: (a) low focus phrases, headed by shenme 什麼, and high focus phrases, headed by bie 別/buyao 不要/bu 不/zhi 只, must be distinguished; (b) different stresses interact with each other. First, it is argued that a low focus marker, i.e. shenme, bears a weak focus stress, and a high focus marker, i.e. bie/buyao/bu/zhi, bears a strong focus stress. Being relatively weak in nature, a weak focus stress assigned on shenme cannot override the nucleus stress assigned on the NP. Instead, it must compromise with the nucleus stress on the NP, resulting in the reanalysis between the two, which in turn bars the size of NPs from being projected into a more complex structure than NP. No such size restriction is found in a high focus phrase, as bie/buyao, being relatively strong in stress, can directly override the nucleus stress on the NP. Second, a contrastive focus stress, assumed to be the strongest, can directly override either a strong focus stress or a weak focus stress; moreover, it can cancel the NP size restriction in the ‘V shenme NP’ construction. This contrastive focus stress, as assigned on an adverb hai 還 or a locative phrase as zai shitang 在食堂 ‘in the cafeteria’, is assumed to be assigned at the phonological/lexical level. Finally, the constraints on the contrastive focus’s cancellation of the weak focus stress are discussed.