Background: Fluency in mathematical language is essential for learning mathematics. Teachers must understand and use their diverse mathematical knowledge, including language and communication difficulties inherent to mathematics instruction. According to recent South African research, Grade 1 teachers are not equipped to utilise learners’ linguistic skills for efficient learning of mathematics.Objectives: This research investigates South African Grade 1 teachers’ mathematical language perceptions, experiences, and feelings. These Grade 1 teachers’ transcripts were analysed to discover their understanding of the language of mathematics.Method: Exploratory, descriptive, and contextual research designs were used in conjunction with an adapted interactive qualitative analysis technique. Focus group interviews, individual interviews, and lesson observations, together with a purposive sampling technique, were used to gather the data from both public and private primary schools.Results: The results showed that Grade 1 teachers view mathematics as a separate language with its own vocabulary and register. The findings highlighted the need to simplify the language of mathematics to enhance understanding.Conclusion: This research concluded that language is essential to mathematics learning and that mathematics has its own register, which is acquired like any other additional language. To help isiXhosa learners understand mathematics in English, scaffolding strategies must be aligned with their linguistic demands.Contribution: This article provides important recommendations for teachers who need to recognise the reality that English is the lingua franca and ensure isiXhosa home language-speaking learners receive the necessary support to acquire actual proficiency in the academic register of English for mathematical language learning.