This study used a copying task to examine spelling acquisition in French and Spanish from a perception and action perspective. Experiment 1 compared French and Spanish-speaking monolingual children's performance. Experiment 2 analysed the behaviour of bilingual children when copying words in French and Spanish. Gaze lift analysis showed that in French, first graders tend to use letter and syllable-sized visual units. The analysis of handwriting production indicated that they used syllable-sized units for motor programming. In Spanish, most words were copied without gaze lifts, as whole orthographic units. The children used units larger than the syllable for motor programming. The results suggest that the differences in the orthographic characteristics of French and Spanish lead to differences in the size of the visual and motor units the children use during spelling acquisition. (Contains 4 figures and 4 tables.)