This study examined image-text relations in English-as-a-foreign-language textbooks focusing on moving-image animations that accompany verbal dialogues. It also explores how animations support verbal dialogues in the textbooks. Data sources include three major versions of junior high school textbooks locally-produced in Taiwan, each consisting of 6 books, one for each semester. Findings show that animations enter into one specific type of image-text relations with the textual dialogue, i.e., a relation of Complementarity: Augmentation, by providing information that is consistent with and additional to the dialogues in a number of ways. The animations provide the rationale for a particular part of the dialogue not otherwise apparent, they portray another participant in the dialogue in addition to the speaker of the conversation turn, and they reveal a speaker's emotional response that is not expressed verbally in the dialogue. In naturally-occurring conversations, these emotions would usually be expressed through interjections, but are mostly absent from the verbal dialogues in these textbooks. As such, the animations also serve to substitute the pragmatic markers that should have been present in the verbal text. Based on these findings, the article concludes by providing pedagogical recommendations for how animations could be used to guide language learners in exploring the possible communicative functions of appropriate interjections in the textbook dialogues in order to develop learners' pragmatic competence.