ABSTRACT. This paper tries to capture the conventionality of natural language in much simpler terms than David Lewis’s, displaying continuity with more rudimentary non-coordinating conventions. Like these simpler natural conventions, natural language conventions do not involve regularities, either de facto or de jure, nor do they require rational underpinnings. This natural conventionality is composed of two simple characteristics: (1) natural conventions are reproduced patterns; (2) they are proliferated due partly to weight of precedent, rather than due, for example, to their intrinsically superior capacity to perform certain functions. These two characteristics are discussed as they characterize simple non-coordinating conventions, then simple coordination conventions, and finally language conventions. The paper argues that the conception of conventions universally adopted in speech act theory is mistaken, and points to a new way of understanding the nature of illocutionary acts.