Introduction -- Challenges and opportunities for second language learners in undergraduate mathematics -- Mathematics in the hands of deaf learners and blind learners: visual-gestural-somatic means of doing and expressing -- Challenging deficit perspectives: student agency in multilingual mathematics classrooms -- Language diversity in mathematics teacher education: challenges across three countries -- Impact of differing grammatical structures in mathematics teaching and learning -- Addressing multi-language diversity in mathematics teacher education programs -- Language diversity and new media: issues of multimodality and performance -- Making use of multiple (non-shared) first languages: state and need of research and development in the European language context -- Purposefully relating multilingual registers - building theory and teaching strategies for bilingual learners based on an integration of three traditions -- Trends in mathematics education in multilingual contexts for indigenous population: experiences from Latin America -- Tensions in teaching mathematics in contexts of language diversity -- Research rationalities and the construction of the deficient multilingual mathematics learner -- Language diversity in research and its consequences -- Using ICTs to facilitate multilingual mathematics teaching and learning -- Mathematics teaching, language policy and the political role of language: perspectives from around the world -- Reflections -- Index.