This study investigated French and Spanish EFL (English as a foreign language) learners' preferred use of three-word lexical bundles with discourse or stance-oriented function with a view to exploring the role of first language (L1) frequency effects in foreign language acquisition. Word combinations were extracted from learner performance data (i.e. argumentative essays), and the frequency of their translation equivalent forms was analysed on the basis of French and Spanish L1 corpora. Strong and positive monotonic correlations were found between the frequency of a lexical bundle in the EFL learners' written productions and the frequency of its equivalent form in the learners' first language. Results also suggest that different patterns of use across the two L1 learner populations may be explained by frequency differences in L1 French and Spanish. Overall, the study calls for a more systematic investigation of L1 frequency effects within usage-based perspectives on second language acquisition.