The second and third sections describe language competencies in more detail: the second section describes effective instructional strategies and the language competencies these require, and the third section describes different types of instructional language and the language competencies these require. [...] The discussion around the first set of issues also provides an overview of the different visions of teachers as language models proposed in the literature, visions that reflect, in turn, the major challenges of providing instruction in French in Canada. [...] Although essential, teachers’ mastery of the language of instruction is therefore not the only factor that influences student learning; language as a cultural vector and the role of the teacher as an agent of cultural transmission are also important in understanding the particular relevance of language competencies for teaching. [...] Such a vision tends to define the language skills of teachers in terms of the disciplinary knowledge they require to teach the language and to use it appropriately. [...] This second conceptualization differs from the first in terms of how it views language competency as extending beyond technical knowledge and mastery of the language to a view of language as a tool and engine of linguistic and cultural vitality for different groups of learners.