Dr. Yim gave a talk at the Asia Pacific Society of Speech Language and Hearing's meeting. The tile of the talk was Importance of Maintaining Mother Tongue in the Face of Bilingual Children's Dynamic Language Shift. Details of the lecture are as follows. This talk will provide an overview of multiple studies of bilingual children, conducted at the Ewha Child Language Lab, whose mother tongues are Korean, Vietnamese, Mandarin, and other languages spoken in Korea. The research aims to provide evidence of the importance of mother tongue on psycho-cognitive linguistic abilities, such as self-esteem, resilience, third language proficiency, and executive functions.