本論文旨在探討動後詞綴“了”與句尾“了”之樹狀結構 (phrase
structure)，分怖上的條件與釋義，以及在“被”字句、“把”字句、動
詞複製結構中的詞尾移位等問題。“了”的語意功能在於表“完成”；此
外，“了”亦寓含強調功用。就句法而論，動後詞綴“了”與句尾“了”
皆可出現於母句或子句中。他們各自位於不同的最大投射結構中(
maximalprojections)。“了”的出現乃透過此〔完成〕特徵(
[perfective] feature)在深層結構中的核對。詞尾必須一步一步地從一
投射中心(head)至另一投射中心移位，然“了”在表層結構中不能為含有
〔恆久〕特徵([permanent] feature)之字元所c-統攝(c-command)。此外
，動後“了”亦不即時出現於CP子句之前；同型“了”亦不連續出現於各
子句中。再者，“被”、“把”、動詞複製結構的第一個動詞皆可為投射
中心(head)，再選接句尾“了”的最大投射結構，此結構可包含另一動後
“了”，動後“了”即可逕自下移至動詞後之詞綴位置。

This thesis aims to study phrase structures of sentential le
and verbal le, conditions on the occurrence(s) and
interpretation of le, and Affix Movement in passive bei,
disposal ba, and verb-reduplication constructions. The
semantic function of le is to indicate completion. Le may also
bear emphatic readings. Syntactically, verbal le and
sentential le can appear in the matrix or embedded clauses.
Further, sentential le is argued to head its own projection
Aspect Phrase (AspP1) and dominates a verbal Aspect Phrase
(AspP2) headed by verbal le. The appearance of le is licensed
by the [perfective] feature in D-structure. And affixes must
move from one head to another step by step. Le with the
[completion] feature can not be c-commanded by other base-
generated element with the [permanent] one. Furthermore, le
immediately preceding a CP clause also renders sentences
ungrammatical; serial occurrences of the same type le are not
favored. Moreover, as heads, the passive bei, the disposal ba,
and the first verb of verb-reduplication constructions can
select or subcategorize for an AspP1 containing an AspP2 headed
by verbal le, lowering directly to the verb.
This thesis aims to study phrase structures of sentential le