TENSE AND TO IN LAYAMON

In Old English, occurs äs a preposition mainly indicating direction and purpose. As such, it also precedes infinitives. In Modern English, the to preceding the Infinitive is a marker of tense. Gradual changes that turn a preposition into an 'auxiliary' are often described äs desemanticization (e.g. Heine and Reh, 1984:258ff. for Ewe) with subsequent grammaticalization, but the actual change of category from preposition to auxiliary is an instance of reanalysis constrained by Universal Grammar and the different stages can be clearly delineated in syntactical terms. I examine the various changes or reanalyses involving to in Middle English. The first takes place around 1275 when the to associated with infinitives is placed in the complementizer position together with for, the second one is complete by 1380 when to becomes an 'auxiliary' placed in the I(nflection) position, indicating non-finiteness. In addition to examining the nature of this change, I discuss aspects of tense within the Government Binding framework: tense is a set of features that must be placed in an appropriate category.