This study looks at natural syntactic processes in the development of verbal mood in first- and second-language acquisition, language change in progress, history, and creolization. Correspondences are examined in the development of the subjunctive vs. the indicative mood. The study presents an integrative perspective, taking into account seemingly disparate linguistic areas in order to reveal universals of markedness. A model of syntactic markedness is proposed that is closely aligned with C. J. Bailey's theoretical views, as well as with Faingold's studies of phonological and morphological development. The model relies on psycholinguistic studies on first- and second-language acquisition, as well as on sociolinguistic variation and change, language history and creolization. The constraints on the development of verbal mood revealed cannot be explained without referring to non-syntactic and non-linguistic factors. Results demonstrate the relevance of second-language learning for markedness theory in particular, as well as for the study of linguistic theory in general, and the relevance of linguistic analysis for foreign language teaching. Pedagogical implications for teaching the subjunctive in American universities are outlined. (Contains 41 references.) (CK)