This study modeled the time-dependent nature of pre-academic skills development for a multi-lingual sample of 382 preschoolers attending Head Start. A two-slope latent variable model accurately described the trajectories, which included five assessment points obtained throughout the school year for both pre-literacy and pre-numeracy variables. Classroom quality and child demographic variables including age, gender, native language (Spanish or English), and disability status served as predictors of growth. Results revealed a reversal effect such that steeper growth from October to March was offset, although not completely, by less growth from March to May. Similar interaction effects were observed for predictor variables and their interaction terms across the two slopes. IEP status predicted less growth, while Spanish-language status predicted increased growth, despite the fact that both were associated with low initial achievement. The complexity of the relationship between classroom quality, native language, disability status, and pre-academic growth is discussed.