In this thesis, I present arguments for a model of language acquisition with three characteristics. These are (1) Continuity in the abstract principles of Universal Grammar; (2) Lexical Learning, or the setting of syntactic parameters based upon the acquisition of morphology; and (3) Morpholexical Learning, which is the abstraction of morphological patterns and generalizations from a lexical database. Continuity accounts for what is invariant in language development. Lexical Learning accounts for what is languageparticular, and which therefore must be learned. Morpholexical Learning accounts for the sequence of developmental stages observed in child language data. The main goal of this thesis is to demonstrate that Morpholexical Learning, in conjunction with paradigmatic structure in the lexicon, provides a model for the acquisition of inflectional morphology. I demonstrate this proposal with data on the acquisition of subject-verb agreement morphology in German. In Chapter One, I present an introduction to the concerns and main proposals of this thesis. In Chapter Two, I motivate the existence of paradigmatic structure with three diachronic case studies. In Chapter Three, I return to the acquisitional debates introduced in Chapter One. I argue that the Continuity Hypothesis represents a preferable alternative to the Maturational Hypothesis. Next, I show that Lexical Learning of clausal representations is superior to the Lexical Projection Hypothesis and the Full Competence Hypothesis. I argue that Morpholexical Learning provides an answer to the Developmental Problem which Continuity and Lexical Learning create. In Chapter Four, I provide an extended case study of the acquisition of subjectverb agreement in German. The construction of word-specific paradigms during the stages under examination accounts for the pattern of agreement errors which German children produce. In Chapter Five, I continue the analysis of paradigm mixture begun in Chapter Two. The patterns of paradigm mixture attested Latin, German, and Icelandic are in essence identical to one another, which suggests universal principles of inflectional organization. In Chapter Six, I conclude the thesis with a sketch of how children develop from the "word-specific paradigm" stage to the "general paradigm stage".