Despite extensive research into the influence of communication strategy instruction on L2 speaking proficiency, the overwhelming majority of empirical-based studies has been conducted with learners whose L1 (in terms of both syntactic and lexical typology) and learning experience share common features with those from the L2 country. Further weaknesses in task design and elicitation methods have resulted in task-determined interactions dictating and limiting the scope and variety of the lexical repertoire of responses. Although substantial evidence (Kongsom, 2016; Rossiter, 2003; Teng, 2012) corroborates the teachability of communication strategies as well as their effectiveness in developing strategic competence, the order of their application, how they are systemised and the selective process behind the management of communication barriers remains less explored. The aim of this thesis is to investigate if strategic language employment is uniformly relied upon or do divergences in usage exist based on, for example, linguistic complexity of the constructs or relevant sociocultural influences. If so, what strategies are selected at the expense of others and which factors are most prominent in the selection process? Clarifying Japanese learners’ selection, employment, and reliance on communication strategies and the rationale behind their selection is the aim of this thesis. In order to investigate strategic language reliance during the management of communication problems, a three-month quasi-experimental study was undertaken in the instruction of 12 wide-ranging communication strategies. Observed interactions of 41 Japanese foreign language learners aimed to assess the relationship between communication strategies and their application during authentic interaction. The findings based on quantitative analysis of the interactions reveal changes in CS employment recorded for the experimental group (most significantly relating to sharp increases of interaction and reduction-based CSs) were greater for those CSs associated with a more active approach and functional determination to achieve a communicative intention. Additionally, qualitative assessment indicates certain sociocultural and existential factors characteristic of Japan must additionally be acknowledged as relevant in CS reliance. Finally, pedagogical application of strategic language instruction is set out to provide EFL Japanese learners with more opportunity to develop productive vocabulary and communication strategy proficiency in order to raise their socio-pragmatic awareness of L2 interactional conventions.