Abstract
1. Introduction
2. The Syntactic Status of English to-Infinitive Particle
2.1 Recategorization of the to-Infinitive Particle
2.2 Grammaticalization: From Preposition to Tense
2.3 The to-Infinitive Is Not Tenseless: to[+TNS]
2.4 C[+TNS]-T[+TNS] vs C[-TNS]-T[+TNS]
2.5 OE: PAffix ⇒ PDE: Tparticle
3. Diachronic Change and Syntactic Variation
3.1 Future Time: Will vs Be going to
3.2 Pto Coordination vs Tto Coordination
3.3. The Syntactic/Semantic Existence of Covert/Null to (= to)
3.4 The Rise of the Split Infinitive
4. Grammaticalization and the Split TP
5. Conclusion
References