Research Findings: Reading e-books is becoming common even among toddlers, but we have limited understanding of how parents-toddlers reading e-books together compares to print books. To address the gap, we investigated interactions of 30 mother-toddler (12 months) dyads, in particular, mothers' language use, while reading both electronic and print versions of the same book. These shared reading sessions were video-recorded. Mothers' perceptions of each shared reading context were also examined by conducting a survey. Data was analyzed qualitatively and quantitatively. The results show that mothers, when using the print book, were more likely to employ strategies to engage their toddlers and focus their shared attention on book content. When using the e-book, mothers tended to provide more support and praise for their children's direct engagement with the book, thereby fostering more independence. While mothers more naturally facilitated the shared reading using the print book, they liked the interactive digital features and their toddlers' high engagement level with the e-book. The results demonstrate how different book formats are associated with different types of mother-child interactions and support different kinds of learning and development. Practice and Policy: Implications for parents and caregivers, and researchers are discussed.