寄生缺口指的是一種必須依附在另一個空語類存在之上的空位。漢語是一個空代詞省略的語言，然而在文獻上它也被視為是具有寄生缺口的語言。我首先提出出現在狀語子句中的空賓語並不能被視為是一個寄生缺口，因為此空賓語的出現並不需要伴隨著非論元移位的發生：此空賓語可以跟論元移位一起存在，或是出現於完全沒有句法移位的句子中。因此，此空賓語應僅是一個因空運符移位而留下的遺跡。其次，我把這分析的觀點運用到被視為擁有真實空位（李艷惠2007）的句子；我提出那些讓李提出真實空位分析的句子事實上可以從牽涉其中的空運符移位是否違反鄰接條件這角度來分析。因此，此研究提出了一個更經濟的方式來處理兩個看似無關但實則高度類似的結構。

Parasitic gaps refer to a specific type of empty category, whose presence relies on that of another empty category. Mandarin Chinese is a pro-drop language, yet it is claimed that this language has parasitic gaps in the literature. I first argue that the empty object position in an adjunct clause cannot be labeled as a parasitic gap, since the existence of this empty category does not need to be accompanied by A’-movement; it can co-occur with A-movement or even appear in sentences with no overt movement at all. Therefore, the empty object position should be merely viewed as a trace left by null operator movement. Second, I extend the proposed analysis to the sentences which are said to have True Empty Positions (Li 2007), proposing that the grammatical contrast that leads Li to postulate True Empty Positions can be boiled down to whether the null operator movement involved in the formation of relevant sentences violates the Subjacency condition or not. This study, thus, provides a more economical way to deal with two seemingly unrelated but in fact highly similar constructions.

空代詞、空運符、寄生缺口、真實空位

pro, null operators, parasitic gaps, True Empty Positions