This paper reports on a cross-linguistic, developmental study of verbal structures and verb types used in two genres of written discourse: personal narratives and expository texts. The study is aimed at (a) establishing the profile of linguistic features that characterize and differentiate these two genres; (b) identifying the developmental changes beyond middle childhood that lead to the proficient use of a full repertoire of verbal structures in the construction of both types of text; and (c) providing fresh empirical evidence for cross-linguistic similarities and differences in the linguistic devices used for Genre differentiation. The paper begins to address these issues by considering quantitative aspects of Genre differentiation in four age-groups (grade-school children, junior high school, high school, and adults) and in five languages (Dutch, French, Hebrew, Icelandic, and Spanish). We expected narratives and expository texts to be characterized by contrasting distribution of the categories that we analysed — verb tense, aspect, mood, voice, and person — across the age-groups and languages under study. To test this prediction, all verbs in our sample were analysed using common coding procedures in all five languages, followed by a statistical analysis of the frequency distribution of each coded category (as our dependent variables) across Age and Genre in each of the languages.