This research explored ways of improving the oral language development of Year 1 children in four low decile mainstream schools who were making limited progress in literacy. Over 82% of these students were Māori. Due to the continued impact of past educational policies and the subsequent interruption of the intergenerational transmission of the mother tongue, many Māori children are not exposed to proficient and fluent models either of spoken English or of spoken Māori. Such children struggle to make the English literacy progress expected of them by schools and communities. The central focus of the research was to evaluate a claim that Year 6 students (tuākana) could make a substantial improvement in the oral language achievement of Year 1 students (teina), through engaging with them in regular conversational contexts using the TALES (Talk, Ask, Listen, Encourage, and Say) procedures. This pedagogical approach is understood as one which was culturally responsive for these students. Quantitative analysis of data from three quantitative outcome measures (Record of Oral Language, Junior Oral Screening Tool, and Auditory-Vocal Association Assessment of Verbal Attainments) demonstrated that there were substantial oral language gains for the 72 teina students involved in the study. The quantitative analysis also demonstrated that these gains occurred most strongly during the phases in which the TALES procedures were being implemented by the 72 tuākana students, in accord with the multiple baseline design. Detailed qualitative analysis of a random sample of six of the 72 pairs illustrated both the effectiveness of the tuākana language interaction with the teina, and the different ways that the tuākana were able to implement the TALES procedure. Analysis of five minute probes of transcripts over six weeks from these six tuākana - teina pairs indicated that a wide range of literacy activities and conversations took place. The unique learning needs and personal learning intentions of each tuakana and teina were successfully monitored using this five minute probe procedure. Powerful reciprocal learning processes were evident in transcripts of conversations between the tuākana and the teina, and also within feedback and feed-forward meetings between the tuākana and key teachers. The substantial oral language gains for the teina students in this study were achieved within learning contexts that were social and interactive, and that embodied the principles of ako (learning and teaching roles were shared) and whakawhanaungatanga (building caring and supportive relationships). These principles are among those that underpin pedagogies that are culturally responsive (Bishop Glynn, 1999; Glynn, Wearmouth, Berryman, 2006; Ladson-Billings, 1995, 2006) and transformative. The results of this research study give a clear message to mainstream non-Māori teachers, that they can make a positive and substantial difference to the learning outcomes of their Māori students.