<p>This study explores the factors influencing English L2 learners’ choices of discourse marker (DM) combinations at the left periphery of conversational turns, with a specific focus on their selection between two competing functional motivations: functional continuation and functional complementarity. While previous research has examined DM combinations across languages, few studies have addressed how learners across different first language (L1) backgrounds navigate these motivations during turn-taking. Distinct from traditional approaches that classify DMs by fine-grained discourse functions, this study categorizes each DM by its (inter)subjective function to better capture learners’ pragmalinguistic decisions at the left periphery of turns. Using a multifactorial framework, we investigate how learners’ second language (L2) proficiency, contextual topic preference, and L1 background jointly shape their functional motivation choices. Analysis of 3423 left-peripheral DM combinations from a conversational learner corpus reveals that more proficient learners tend to favor functional continuation, combining two subjective DMs especially in topics related to personal experiences and impressive films. Conversely, less proficient learners tend to exhibit a preference for functional complementarity, combining intersubjective and subjective DMs in topics such as a visited country. Furthermore, the source syntax of DM combinations differs by functional motivations. These findings highlight L2 speaking proficiency and L2 syntactic knowledge as primary factors in combining left-peripheral DMs, with sociopragmatic awareness and L1 background as secondary factors. Additionally, the preference for functional continuation across L1 backgrounds indicates a potential interlanguage communicative universal.</p>