Data from a language development project at the Polytechnic of Wales were used to compare the speech and writing of 48 monolingual English-speaking children. The 48 children came from three groups, aged 8, 10, and 12. For the collection of spoken data, the children, divided into groups of three, were tape recorded while they made a construction out of Lego bricks. They were then interviewed individually and asked to describe what they had made and to talk about other games they played. For the writing task, the children had to write about the Lego construction they had built. The spoken data yielded eight different oral constructions--all of which occur in the spontaneous speech of adults: the clause initiator, "well"; the use of "this" and "these" for specific indefinite reference; the recapitulatory pronoun; colloquial uses of "like,""sort of," and "kind of"; the tag statement; and amplificatory noun phrase tag. All of the constructions, apart from the recapitulatory pronoun, showed an increase from age 8 to 10. Interestingly, many children learned to avoid specifically oral constructions in their writing by about the age of ten, and some had begun to use specific literary constructions in their writing that did not occur in their spontaneous speech. (HOD)