Planning for language teaching and learning within the context of immersion instruction requires a high degree of teacher language awareness and proficiency. However, gaps noted in such critical skills constitute a significant obstacle to these teachers whose responsibility is to be proficient models of the immersion language, display a broad range of advanced linguistic skills and competencies and integrate content and language learning in meaningful ways (Ó Ceallaigh & Ní Shéaghdha 2017, Ó Duibhir 2018). Concurrently addressing content, language and literacy development through their students’ second language poses significant challenges (Cammarata & Haley 2018; Cammarata & Tedick 2012; Cross 2016; Fielding & Harbon 2017; He & Lin 2018; Lyster 2007; Ó Ceallaigh et al. 2018; Tedick & Lyster 2020) that calls for significant teacher preparation and professional learning opportunities (Lyster & Ballinger 2011; Lyster & Tedick 2014; Turner & Fielding 2020).

This paper will report on how a model for building linguistic proficiency underpinned by the principles and practices of the Common European Framework of Reference for Language (Council of Europe) was designed, developed and delivered to cultivate the linguistic capacity of 113 immersion teachers as they engaged with a blended learning postgraduate program centred around content and language integrated learning. The progress of the language users will be demonstrated on a language learning continuum from level B1 (Independent User) to level C1 (Proficient User) of the framework and aligned with the tools, supports and scaffolds implemented through an action-orientated approach to support the language development.

Findings suggest that the incorporation of a model for building linguistic proficiency towards level C1 of the CEFR played a pivotal role in enhancing the linguistic resources of immersion language teachers and fostering learner autonomy, motivation, and success. Learners were empowered to plan, to monitor and reflect on their own learning, provide evidence of progress, share insights and come up with creative solutions. This process challenged them to become proficient users of the immersion language and in turn promoted self-regulated and action-oriented language learning. This research provides valuable lessons in the acquisition and development of language by immersion teachers and argues that a model for building linguistic systems and mapping linguistic progress is adaptable to similar language and teacher education programmes.

Keywords: Building language proficiency, blended learning, content language integrated learning, action orientated approach.