A large study which investigated the nature of dyadic interactions in a university second language (ESL) classroom setting found that students form very distinct and stable relationships or patterns of dyadic interaction. This paper uses a case study approach to illustrate two of the patterns found in the study: a collaborative pattern and a dominant/dominant pattern. These distinct patterns were evident in the way the pairs approached the task, dealt with any language issues as well as a number of salient features such as the quantity and quality of requests, explanations, phatic utterances and repetitions. The study also considered whether there were instances in the data to suggest a transfer of knowledge from the pair talk to subsequent individual performance. The study found that there were a number of such instances in the data of the collaborative pair but none in the dominant/dominant pair. These findings suggest that the relationship a pair or group forms is an important consideration in research on learner interaction and in second language pedagogy.