This study investigates the formal verbalizations of evaluation used by four beginning L2 learners of Finnish from a dynamic usage-based perspective. Longitudinal data collected weekly were used to investigate what kind of constructions learners use to express evaluation and how these interact and develop over time. The results show that when a new construction is acquired in the L2, another related construction might regress. The results also point to increased variability in the construction during a phase of rapid development and reduced variability in the phases of regression or slower progress. These findings add to our understanding of a developing L2 as a system in which changes in one aspect have the potential to bring about changes in interconnected aspects. The variability patterns found in the learners' developmental trajectories add to the growing body of research that proposes variability as meaningful in the learning process.