Swedish early childhood education (ECE) offers a curriculum-based preschool for children aged one to five, and a preschool class for children aged six years. Activities in these programs have traditionally been based on play and having fun, avoiding structured activities with formal learning objectives. Due to indications that Swedish ECE has failed to use its resources to stimulate children's learning, the revised ECE curriculum now contains discernible learning objectives. This study analyses the process by which preschool teachers shifted their emphasis when participating in an learning study based on three projects conducted in Swedish ECE practice. In total, 14 preschool teachers, 95 children (2-6-year-olds), and five researchers participated. The objects of learning were: (1) 3D geometrical forms (2-3-year-olds), (2) organic decomposition (4-5-year-olds), and (3) the concept "twice as" (6-year-olds). The empirical material comprises 278 pre-, post-, and delayed post-tests, twelve planning meetings, and nine teaching activities. The results indicate that, during the projects, the initial focus on mere play expanded to include a focus on the object of learning. Three modes of change were discerned in how (1) the activities were framed, (2) the learning was perceived, and (3) the learning activities were conducted.