This study examined the distribution of two Hebrew nominal structures - N-N compounds and denominal adjectives - in spoken and written texts of two genres produced by 90 native-speaking participants in three age groups: eleven/twelve-year-olds (6th graders), sixteen/seventeen-year-olds (11th graders), and adults. The two constructions are later linguistic acquisitions, part of the profound lexical and syntactic changes that occur in language development during the school years. They are investigated in the context of learning how modality (speech vs. writing) and genre (biographical vs. expository texts) affect the production of continuous discourse. Participants were asked to speak and write about two topics, one biographical, describing the life of a public figure or of a friend; and another, expository, discussing one of ten topics such as the cinema, cats, or higher academic studies. N-N compounding was found to be the main device of complex subcategorization in Hebrew discourse, unrelated to genre. Denominal adjectives are a secondary subcategorizing device emerging only during the late teen years, a linguistic resource untapped until very late, more restricted to specific text types than N-N compounding, and characteristic of expository writing. Written texts were found to be denser than spoken texts lexically and syntactically as measured by number of novel N-N compounds and denominal adjectives per clause, and in older age groups this difference was found to be more pronounced. The paper contributes to our understanding of how the syntax/lexicon interface changes with age, modality and genre in the context of later language acquisition.