This article reports on some of the findings of an Economic and Social Research Council (ESRC) funded project that looks at the mark-making of children under three years old. The data were all collected in the children's homes, and multimodal transcription and analyses were used. The project focused on an investigation of the principles that children use when they first start to construct signs that associate the making of marks with the representation of personal meanings, including those that relate to systems of writing. The article is set in the wider context of discussion of related educational practice. Two findings are discussed in detail, with a presentation of exemplar evidence from analyses of the mark-making of two of the children. In the first, the relationship between marks made by young children, and systems and notations of drawing, writing and number is considered; evidence from this research suggests that while they draw on these systems, young children produce graphic signs that have an independent status, and that have relational structures that refer to other signs within the text, as well as to external objects and experiences. The second finding looks at how children use everyday social and bodily experiences to evolve predictable mark-making structures, and examines this process of grammaticization in a child's construction of an inventory. (Contains 14 figures and 3 notes.)