英文動名詞子句中主詞常以所有格呈現，有時又以其他格位呈現，本研究探討這些格位變化之現象，以及如此呈現之原因。Abney（1987）提出DP理論假說，主張DP與IP有相似結構，都是功能詞的最大投射；功能詞I以語意詞彙動詞的最大投射作為其補語，功能詞D則以語意詞彙名詞的最大投射作為其補語。本研究以DP理論說為基礎，主張英文動名詞子句是DP結構，並以此分析主詞所有格呈現之由來，以及當英文動名詞子句在不同句法位置時，格位變化之原因及呈現方式。本分析對動名詞子句中功能詞D與格位授與的關係，進行充分的說明，並對英文動名詞子句與其他一般補語子句的運作相似現象一併闡述。

In this study the genitive case and case variations of the subject in a gerund clause are examined to interpret why and how it is thus case marked. Following Abney's (1987) DP Hypothesis that DP and IP are similar in that like I, D is a functional head that takes the maximal projection of a lexical category, i.e. NP in this case, as its complement, we propose that the English gerund clause is actually a DP in structure. With such analysis, the varying case manifestations of the subject in gerund clauses can be accounted for in a theoretical system and the parallelism between gerund clauses and regular complement clauses, finite or nonfinite, can be fully understood.