This book describes a study on the question of what sort of innate knowledge it is that enables children to acquire a first language. The author, using a computational approach, builds a model, named BUD (Bring Up a Daughter), on the basis of the data linguists and psychologists have collected.BUD is based on the empirists, view of first language acquisition (as opposed to that of the nativists'), that children make a number of rules in acquiring a first language and that over generalizations can be found in the acquisition of every aspect of a language. Thus, BUD has no built-in procedure by which it computes the structures of a language. A detailed description of the BUD model and its workings answers the question on which the study is based.