A central goal of typological research is to characterize linguistic features in terms of both their functional role and their fit to social and cognitive systems. One longstanding puzzle concerns why certain languages employ grammatical gender, which assigns nouns to distinct classes and marks neighboring words for agreement. While historically noun classification has been viewed as a useless ornament with little apparent rhyme or reason, there is an accumulating body of evidence that native speakers use determiners to guide lexical access. Here, we compare the communicative function of gender marking in German (a deterministic system) to that of prenominal adjective use in English (a probabilistic one), finding that despite their differences, both systems efficiently smooth information over discourse, making upcoming nouns more equally predictable in context. We hypothesize that evolutionary pressures may favor one system over another on account of how easy they are for children and adults to acquire.