A major issue in the study of language change is the degree to which individual speakers participate in ongoing linguistic changes as these progress over time. In this study, we examine the hypothesis, suggested by research based on the apparent-time model, that in any given period most people are neither progressive nor conservative with regard to ongoing changes, but rather fall between these polarities. Our data come from the Corpus of Early English Correspondence, which spans over 270 years. A computational model was developed to establish which language users were progressive and which conservative with respect to several ongoing changes that progressed in real time between the early 15th and late 17th centuries. The changes studied ranged from morpheme replacements to more structural patterns. Our results indicate that the degree to which language users participated in changes in progress depended on the type of language change analyzed, the stage of development of the change, and the rate of diffusion of the process over time. The model also enabled the identification of groups of leaders of linguistic change in Tudor and Stuart England.