This paper explores the hypothesis that diminutive usage in child-directed speech may provide multiple benefits for language acquisition. It summarizes a series of experiments that exposed naïve English-speaking adults to Dutch or Russian diminutives, and tested their ability to isolate words in fluent speech or acquire gender categories. Across studies, adults benefited from exposure to diminutives over their simplex counterparts, supporting the hypothesis that diminutives simplify word segmentation and morphology acquisition, by increasing word-ending invariance, regularizing stress patterns, and decreasing irregularity in morpho-syntactic categories. A similar diminutive advantage is observed in experimental studies of first language acquisition: Preschool children produce fewer gender agreement and case marking errors with diminutives than with simplex nouns across several languages (Russian, Serbian, Polish, Lithuanian).