This study in Kano State, Nigeria, uses a quasi-experimental design to investigate the effectiveness of two teacher training programmes (ESSPIN and Jolly Phonics) in 536 government primary schools. In total, 5,449 children were tested using the phonics screening check to determine which teacher training programme positively affects learning. The effects are greater when teachers have completed two different programmes using adaptive instruction and include elements of coaching and mentoring. A pupil whose teacher has undertaken both training programmes will score 6.062 (p < 0.001) points higher in Primary One and 4.344 (p < 0.01) points higher in Primary Two. English spoken in the home, being a boy, and being older in your year group have a significant positive effect on word reading score. This research highlights the importance of meaningful and impactful teacher training on children's reading development in English, the medium of instruction in Nigeria from the 4th year of primary school.