NNESTs have diverse educational backgrounds. For example, a number of non-native English-speaking teachers (NNESTs) have obtained their degrees abroad in English-speaking countries and have returned to their countries in English-as-a-foreign-language (EFL) contexts, working alongside NNESTs who have been educated domestically. Yet, little is known about how such EFL-educated NNESTs assert their identities as legitimate English teachers while encountering those colleagues who have been educated in English-speaking countries as well as those who are native English speakers. Few studies have illustrated the complexity and tensions EFL-educated NNESTs encounter as they position themselves as legitimate English educators and English speakers. Focusing on two Taiwan-educated Taiwanese teachers of English and drawing on concepts of capital and agency, this qualitative case study investigates how the linguistic capital of the English language serves as an essential prerequisite for being considered legitimate English educators in Taiwan. This study also examines why earning this highly-valued linguistic capital and being able to turn their capital-gaining experience into one of their pedagogical resources enabled Tera and Guan to assert themselves as legitimate English teachers, in considering the sociopolitical, institutional, and teaching contexts where these teachers worked. This study also offers an analysis of the interconnectedness of agency and capital. Lastly, it further examines how the teachers did not think they shared the ownership of the English language, despite being excellent English speakers and users. Suggestions are provided for NNEST pre-service language teacher education and ongoing professional development.