ABSTRACT The development of the expression of definite versus indefinite reference in Finnish, a language which lacks articles, will be studied by examining narrative data collected from 3-, 4-, 5-, 7-, and 10-year-old native Finnish-speaking children and adults. This data will be compared to similar data from speakers of article-bearing languages (English, German, and Spanish), as well as one non-ariticle-bearing language (Turkish), to determine how and the degree to which Finnish, a Language which expresses definiteness in a variety of ways, influences the child's acquisition and use of this semantic/pragmatic category. In comparing the acquisition of article-bearing and non-article- bearing languages, this research will also provide further insight into the basic Operating Principles that children bring to the acquisition task. This research also begins to fill the gap of discourse-oriented studies on the acquisition of Finnish, focussing on a much larger age range than previously dealt with as well.