How do humans acquire, at a very early age and from fragmentary and haphazard data, the complex patterns of their native language? This is the logical problem of language acquisition, and it is the question that directs the search for an innate universal grammar. As Time Goes By extends the search by proposing a theory of natural-language tense that will be responsive to the problem of language acquisition.

The clearly written discussion proceeds step-by-step from simple observations and principles to far-reaching conclusions involving complex data carefully selected and persuasively presented. Throughout, Hornstein focuses on the logical problem of language acquisition, highlighting the importance of explanatory adequacy and the role of syntactic representations in determining intricate properties of semantic interpretation.