While the past few years have seen a growth of research exploring changes in second language (L2) motivation over different timescales, the construct of engagement and its relationship with motivation in the L2 classroom have remained relatively underresearched in the field of Second Language Acquisition (SLA) from a dynamic perspective to date. The present study seeks to examine variability in L2 motivation and four subsets of student engagement (i.e. behavioural, cognitive, emotional and social) over the course of four single lessons and throughout the academic year, and to explore the interconnections between the two constructs.

The research comprises a set of data drawn from five classes of French and Spanish at different proficiency levels at a British university. Inspired by MacIntyre and Legatto’s (2011) ‘Idiodynamic Method’ and by Waninge, Dörnyei, and de Bot’s (2014) ‘Motometer’, the research method developed for the present study allowed (a) to capture micro- and macro-fluctuations in motivation and engagement, and (b) to explore the complex interplay of variables that mediate this relationship. The participating students rated their motivation every 2.5 minutes based on a replay of the lesson on a tailor-made chart. During follow-up cued interviews they were asked to provide a rationale for their changes in motivation and engagement during the lesson. Classroom observations were
also conducted for triangulation purposes.

Findings suggest that both motivation and all four subsets of engagement were subject to periods of change and stability over time; their changes emerged from the mutual interactions between the learner and the classroom environment. Furthermore, the relationship between the two constructs appeared as dynamic and non-linear. This was mediated by the complex interplay of intrapersonal, behavioural and contextual variables.