The year 2020 celebrates the 40th anniversary of Thailand TESOL and the return of our colleagues, Pan-Asian Consortium (PAC), to Thailand. This event marks the consolidation of TESOL professionals, practitioners and stakeholders with different cultures and beliefs to make differences in the world of language learning. Diversity in all aspects of TESOL also needs immediate responses in terms of innovative research and professional practices. At the Thailand TESOL-PAC 2020 conference, our TESOL friends and colleagues from all corners of the world are welcome to share expertise, to raise issues and to solve different problems so that we can respond to the diverse needs of different learners and teachers as well as different learning situations and platforms in the transcultural society.