The performative hypothesis is the hypothesis (proposed in Ross 1970), that every sentence is associated with an explicit illocutionary act, i.e. is derived from a deep structure containing a performative verb.
Sentence (ia) is derived from (ib), or perhaps (ic):
(i) a I'll write you next week b I claim I'll write you next week c I promise I'll write you next week
- Ross, J.R. 1970. On Declarative Sentences, in:R.A. Jacobs adn P.S. Rosenbaum, eds. Readings in English Transformational Grammar, Ginn: Waltham, Mass