The study of communication strategies (CSs) in Content and Language Integrated Learning (CLIL) has mainly focused on crosslinguistic influence as a CS. Thus, there is a need of studies that tackle other CSs such as target language-based strategies together with crosslinguistic influence. Furthermore, most of CLIL studies have compared CLIL to non-CLIL learners (i.e. Celaya and Ruiz de Zarobe 2010; Martínez-Adrián and Gutiérrez-Mangado 2015) and few (pseudo)longitudinal studies have been conducted to the present date (i.e. Lázaro Ibarrola and García Mayo 2012; Lázaro Ibarrola 2016). Additionally, there is a lack of studies addressing a correlation between the use of CSs, general proficiency, as well as receptive vocabulary measures.This paper examines the use of crosslinguistic influence (L1 Spanish/L2 Basque) as a CS (interactional strategies and transfer lapses: borrowings and foreignizings) together with target language-based strategies (analytic and holistic) in an oral narration task in two different age/proficiency CLIL groups of L3 English secondary-school learners. It also correlates the findings obtained with the results from a general proficiency level test and a receptive vocabulary level test.Results indicate that proficiency does not have a big impact on the use of these strategies, as no differences were found between the groups. Regarding the distribution of strategies, holistic strategies are the most used, which could be due to the overriding effect of CLIL (i.e. Martínez-Adrián, Gallardo-del-Puerto, & Basterrechea, in press). With respect to correlation analyses, although crosslinguistic influence seems to go hand in hand with proficiency level and receptive vocabulary, this does not apply to the use of target language-based strategies. Additionally, the use of target language-based strategies does not imply a lower use of prior linguistic experience, which seems to indicate that crosslinguistic influence, as a tool to scaffold L3 production, is still relevant in these CLIL learners.