This article is based on the main finding of an action research study that investigated how primary school teachers could improve the teaching of fractions. The study primarily focused on what pedagogical strategies might be employed when shifting teaching and learning from procedural application to conceptual understanding. The research aimed to unpack what key elements of lesson design could be utilised to raise student achievement and understanding of fractional concepts. Language development was deemed to be one of the most beneficial to the teachers' practice and the research team explored the significance of developing shared mathematical language and the important role vocabulary plays in conveying meaning and internalising understanding. The journey of two teachers is described here in this article. [Note: The publication year (2024) shown in the citation on the PDF is incorrect. The correct publication year is 2025.]