情态是系统功能语法中人际功能的重要组成部分。商品广告通过广告语言来引导消费者,对广告语的情态分析,从而更好的帮助我们分析其语言的人际功能。本文运用韩礼德的系统功能语法对英文商品广告语篇中的情态量词、情态取向及相应的情态责任展开研究,从而发现情态在英文商品广告语篇中发挥具体的人际功能作用。 Modality is an important part of interpersonal function in system function grammar. Advertising through advertising products to guide consumers, the modality of the slogan to better help us analyze the language of their interpersonal function. This article uses Halliday ’s system functional grammar to study the modal quantifiers, modalities and corresponding modalities in the texts of English commercial advertisements, so as to find out that modality exerts specific interpersonal functions in English commercial texts.