Diverse learners' backgrounds necessitate bilingual (Mandarin and Cantonese) and biliterate (simplified and traditional characters) personal switching in Chinese language education. Authentic language learning materials bring fresh topics that connect learners with the real world and awaken their interest in language learning. In this study, IntroCOVID-19 ebooks were designed to provide an introduction to the disease, depict the stories happening during the pandemic, and allow students and teachers to select phonics and characters based on their individual needs. Customized IntroCOVID-19 incorporates five modalities that can increase students' interest in language learning: texts, images, audios, animations, and instant interactions. To examine the usability, a user study was conducted with 33 Chinese language learners and 20 teachers. Findings confirm that personalized IntroCOVID-19 ebooks enable linguistically diverse learners' conceptual understanding of COVID-19, engage learners with authentic learning, and assist teachers with less technological background to teach language that meets students' different needs.