Teachers’ and teacher educators’ individual theories, attitudes and beliefs underlying their daily practice, are often challenged by sociolinguistic changes, curricular innovations, or new language policies that may often trigger teachers’ resistance to change, particularly when they are required to adapt and revisit their teaching practices. In many European countries recent migration flows have modified the countries language landscapes; their school population is now growingly plurilingual and with different learning and language needs. In their out-of-school experiences, learners are more and more exposed to English through social media and to non-native speakers’ English (ELF), aspects not integrated yet in local language policies, nor in teacher education programs. It is thus important to design pre- and in-service teacher education programs aimed at sensitizing language and subject teachers to these new scenarios, using reflective practice approaches in multilingual contexts. These contexts require English language teachers, and teachers who use English in different fields such as Content and Language Integrated Learning (CLIL) or English Medium of Instruction (EMI), to reconsider their personal assumptions and beliefs, and to develop new competences that would incorporate the powerful reflective framework provided by ELF-awareness. The ELF-aware perspective had been adopted in recent courses for English teachers carried out in Italy, as the ENRICH CPD course, and in the CLIL courses for content teachers. The aim of this contribution is to present and discuss findings of two research studies carried out within the above-mentioned courses that were meant to make teachers aware of new instantiations of English through a reflective practice approach such as the ELF-aware approach, and to sustain their professional development as well as their agency. This paper is mostly related to the lessons learnt from the findings from teachers’ responses to course innovations and their agency development during these courses.