This paper constitutes the initial phase of a large-scale research project that aims to explore the relationship between inter- and intra-individual difference factors in foreign language (L2) acquistion. In an effort to lay the groundwork for a systematic approach to this burgeoning area of research, the present study overviews previous theoretical insights and empirical findings associated with the potential constructs of linguistic sensitivity and proposes a tentative model that is practically useful for designing a measurement tool. The model consists of four dynamic dimensions: mode-sensory preferences in language processing and use, sensitivity scales in each component of linguistic competence, inclinations in language function, and finally metalinguistic consciousness and strategic control for development. Based on this model and data collected from interviews with L2 learners and expert reviews, a self-reporting questionnaire with 62 items is constructed that can effectively address the needs of profiling learner characteristics in classroom settings as well as the goal of subsequent research efforts to investigate the role of linguistic sensitivity in L2 learning and teaching.