In this corpus-based study we explore three measurements of L2 fluency – articulation rate, filler particles, and pauses –, both within and between two registers of spontaneous dialogues spoken by Polish learners of German. The measurements are assessed both in toto (as calculated over the whole dialogue) and in parte (as calculated for specific sections). The sections are identified on a quantitative tier that divides the dialogue into four parts, and qualitatively on two linguistically-informed tiers, comprising sections based on dialogue move and task. We challenge the assessment of fluency as an average measurement over the entire dialogue, showing that a sectionwise analysis offers a better understanding of similarities and differences both within and between the two registers.