Aotearoa New Zealand is a diverse multicultural nation, with a vibrant indigenous culture and language. However, levels of bilingualism are relatively low, with less than 20% of the population using more than one language. English is the dominant language, and monolingualism in English the taken for granted norm. In the New Zealand Curriculum (2007), there are prevalent themes of multiculturalism, diversity and inclusion, yet the role of languages in each of these is ignored, and bilingual ideals are largely invisible. This article takes up the 'problem' of monolingual bias in New Zealand education, particularly in relation to children from linguistically diverse backgrounds in primary classrooms. Using classroom-based data to highlight the silences and deficit discourses that attach to the notions of language diversity and bilingualism in regular classrooms, I suggest that some fundamental shifts are needed to overcome the negative effects that result from persistent English monolingual bias.