英语中屈折成分的优选分析

管约论（Government-binding Theory）把涵盖多种语法特性，特别是时态、人称和数的抽象组构成分称作屈折成分，通常缩写为INFL。INFL的最大特点是不能独立存在，这个特点体现在优选论中就是限制条件＋INFL。此限制条件在英语中的层级排列很高，根据优选论的原则，层级排列越高的限制条件越要优先满足，因此就产生了一系列与INFL有关的句法现象，包括INFL的下降式位移（lowering movement），助动词插入屈折投射（auxiliary insertion to D，和dc-支持（do-support）。

An Analysis of INFL in English by Optimality Theory

Inflection, which is abbreviated as INFL, refers to a series of abstract grammatical items, including the tense, person and number. Within OT, INFL is required to be bound with some lexical item by a high--ranked constraint, ＋INFL. Following the rule that the higher ranked constraints have more privileges to be satisfied, some syntactic operations occur to satisfy ＋INFL though some lower ranked constraints are violated because of it. Lowering of INFL is punished by PR-BD, but in an English declarative, which involves no auxiliaries, it is the best policy to fulfill ＋INFL. In a sentence with the auxiliary, the lowering operation becomes unnecessary because the auxiliary is inserted directly to carry INFL. This operation is called auxiliary insertion. In other cases like negatives with no auxiliaries, dummy elements are required to be inserted into I carrying INFL for the lowering of INFL is blocked by NegP.