This self-study action research set out to address the question: How can I implement effective strategies to support children's use of mathematical language and their problemsolving in my First Class classroom? Motivated by a desire to make mathematical thinking more visible and accessible to young learners, I designed and implemented a twelve-lesson intervention focused on developing precise language and collaborative reasoning in mathematics. Each lesson followed a three-part strucrure. To begin, I introduced key vocabulary, and question stems through structured mathematics talk routines designed to model clear mathematical communication. This was followed by a story-based component, where I used mathematical picture books to prompt discussion, reinforce new language, and build conceptual understanding in context. Lessons concluded with student-led problem-posing activities, encouraging children to apply language meaningfully by creating their own mathematical problems and engaging in peer explanation. Data collection included reflective joumaling, student work samples, classroom observations, critical friend 's questionnaires and lesson feedback, student's questionnaires, and informal dialogue with pupils. The analysis revealed three key themes. First, adapting my teaching approaches to include discussion, storytelling, and collaborative tasks created more space for mathematical thinking. Second, building and scaffolding mathematical language through modelling, repetition, and meaningful use was crucial in helping students articulate their reasoning. Third, promoting student ownership and autonomy through problem creation and peer teaching fostering deeper engagement, confidence, and responsibility for learning. Engaging in this self-study deepened my understanding of the role language plays in early mathematics and highlighted the value of reflective, responsive teaching. The process not only improved my pupils' ability to express and apply mathematical ideas but also supported my ongoing development as a learner and educator.