I examine the development of for to and for in several stages of English. I argue that as prepositions grammaticalize, they acquire certain intrinsic features and occupy special positions. In Old English, for to is a P, related to Case, and has some future sense (through an extension of the locative meaning). Verbs do not subcategorize for complements with for (yet), however. In early Middle English, for to is used to introduce a complement with future meaning. Now, for (to) occupies C, which I assume is universally true for purpose/future indicators. In late Middle English, the situation solidifies, and more verbs select a complement with for (to) indicating purpose and futurity. In Early Modern English, for to disappears, but for separated from to takes over its function of introducing purposive adjuncts and future complements.