The role of languaging in second language acquisition (SLA) has been widely investigated since its postulation in the 1980s, though only a few studies have addressed languaging in speech act production as an aspect of second language (L2) pragmatic development. The present study was designed to compare the nature of languaging produced by 45 intermediate English as a Foreign Language (EFL) learners while completing five apology and five request written discourse completion tasks (WDCTs) individually (N=15) and collaboratively (in pairs) (N=30; 15 pairs). Following a two and a half-hour workshop, individual think-aloud protocols (totalling 304 minutes) and paired interactions (totalling 392 minutes) were transcribed. Subsequently, episodes of noticing, reflection and hypothesis testing, as the three main functions of languaging, were detected in the transcripts. They were coded by two coders based on a coding scheme specifically designed with reference to speech act production. The coded episodes were then subjected to qualitative comparisons. In general, the analyses revealed the greater potential of collaborative languaging to induce the noticing of more social context variables (SCVs) involved in performance. Collaborative languaging also nested comparative and more profound reflections, as well as successful output modifications following the greater number of hypothesis testing episodes it led to. The findings are discussed in light of the sociocultural notions of inter-psychological learning mechanisms involved in collaborative dialoguing.