There is a growing literature in philosophy dealing with the phenomenon of inner speech, that is, the activity of speaking to oneself in one’s mind. This paper highlights a feature of inner speech which has not yet been noticed in this literature: that there is something distinctive that it is like to make a sincere assertion in inner speech. The paper then traces out two implications of this observation. The first relates to the question of how we should characterise inner (...) speech; the second relates to the question of how inner speech may play a role in self-attributions of belief. (shrink)