Pil - Hw an Lee . 2002 . On the Dev elopment of Eng lish Infinitiv al Cons tructions . S t ud ie s in M od e rn Gram ma r 27, 77- 104 . This is an explanation for the development of the three infinitival constructions which were introduced into English roughly at the same time during the Middle English period, i.e., the so- called Accusitiv cum Infinitivo (or exceptional case-marking ) construction, the f or NP to V construction, and the passive infinitivals . There have been various accounts for the introduction of these constructions . The traditional accounts are synt actic borrowing from Latin and analogical extension. However, Fischer (1988, 1989, 1990, 1991, 1992a, 1992b, 1994) criticizes such accounts, saying that the introduction was due to grammar - internal factors, expecially to the word order change English underwent in this period. It is argued in this article that the loss of inflectional endings is a more important internal change than the word order change. The argument is that the reanalysis, by which new infinitival constructions appeared, was due to the loss of inflectional ending (especially, dative ending ) of the sandwiched NP between the main verb and the infinitive. Furthermore, there is a general agreement that the word order change in English was it self due to the loss of inflectional endings. In this respect , the loss of the inflectional endings is a more basic and important factor for the changes of English Infinitival constructions .