本文從「功能語法」的觀點，特別是根據「從舊到新」的功能原則，來討論華語的「引介句」（包括「有無句」、「隱現句」、「存在句」、「氣象句」等）、「從屬子句的移後」與「主題句」等句式，並與相對應的英語句式來做這兩種語言之間的對比分析。所謂「從舊到新的原則」，指的是造句的時候，要考慮前面的文章或言談的情境，把代表「舊的次要信息」的句子成分盡量放在靠近句首的位置，而把代表「新的重要信息」的句子成分盡量放在靠近句尾的位置。這樣簡單明確的原則卻能妥當說明華語與英語之間的「‘有’字句」與「'there is'句」、「‘在’字句」與「'NP is'句」、「隱現倒裝句」與「方位倒裝句」、「氣象倒裝句」與「填補詞主語句」、「假及物句」與「'Have NP V-en'句」、「對稱謂語句」、「主題句」等句式之間的對應或對立，並且可以應用於作文與翻譯教學上面來。

The present paper discusses, from a viewpoint of functional grammar, especially based on the "From Old to New Principle", Chinese presentative sentences, which include existential sentences and meteorological sentences among others, in contrast with the corresponding English sentence patterns. The so-called "From Old to New Principle" can be summarized as "the sentence elements representing old and less important information are to be placed as near the sentence-initial position as possible while those representing new and more important informantion are to be placed as near the sentence-final position as possible". This seemingly simple and direct principle, however, can be used to account for the differences in the functional perspectives of various sentence patterns in English as well as in Chinese, and thus provides a useful instrument not only to a contrastive analysis involving the two languages but also to teaching translation from one language to the other.