Despite the recent emergence of corpus pragmatics, the use of corpus linguistic methods in interlanguage pragmatics remains limited. This study employs corpus linguistic methods to shed light on recurring patterns of use within a speaker group over time and also between speaker groups. We examine the extent to which a group of 33 Anglophone learners of German develop their knowledge of pragmatic routines in realising apologies in study abroad. Data was elicited via a production questionnaire and baseline data was also gathered. Corpus-driven methods reveal the primacy of explicit apologies in the data and facilitate an in-depth, fine-grained quantitative and qualitative analysis of these pragmatic routines by learners and native speakers alike. As such, the analysis incorporates the traditional level of the strategy, but also goes beyond it to focus on the formal level and investigate routine variants, routine modifications and learner-specific realisations. Findings reveal several unchanging features of learner apology behaviour over time, including a stable and heightened learner preference for explicit apologies relative to an L2 norm and an unchanging dependency on the realisation of these explicit apologies via a single routine expression. Developments towards an L2 norm are also recorded, as are non-linear developments frequently involving increases in learner-specific realisations. The path followed by a routine is shown to be dependent on an array of factors, including whether another form fulfils the same function, how complex a particular routine is and whether an equivalent routine exists in the L1. The article closes with a discussion of the potential for using corpus linguistic methods as a means of investigating routine development.