Knowledge accumulates across the lifespan, yet most research into its effects on language comprehension has focused on young adult college students. This leaves a critical gap in understanding how knowledge impacts comprehension in other populations, including healthy older adults. Older adults bring greater language experience and knowledge to comprehension tasks but also must contend with changes in cognitive factors like processing speed and working memory. We still know little about how older adults use their knowledge in real time and thus how basic comprehension abilities, which seem relatively stable across the adulthood, may arise from the use of different types of representations or processing mechanisms. In this talk, Melissa Troyer presents studies examining how differences in experience shape the processes involved in language comprehension, including both differences in specific knowledge (i.e., domain knowledge) and due to age. Combined with extant research, our results suggest that as individuals gain knowledge, comprehension may become more precise and less exploratory, and perhaps less predictive, likely due to in part to more modularly organized semantic networks. However, our research also suggests that even among “experts,” there is still opportunity for exploration and learning via prediction. These findings point to long-term, experience-driven developmental differences in how people process and likely learn from language that are protracted and occur across the lifespan.