Grounded theory (GT) is mainly identified as (qualitative) methodology for detecting a grounded, i.e. data-driven theory concerning structure- and action-bound dimensions of studied phenomena. Developed by the American sociologists Strauss and Glaser, GT inquiry has primarily centered on health and illness issues, feminism, race and ethnicity and schooling and education. Only some GT studies relate to teaching and acquisition of (first, second etc.) languages. Its research tenets of 'theoretical sensitivity' and openness are controlled by its 'methodically controlled FREMDVERSTEHEN'-approach. Theory construction is computer assisted over the last decade (cfr. CAQDAS) and GT might apply Schmid's (2011) theory of actions and social mechanisms to suitably connect structure- and action-bound matrix dimensions. Though GT is well elaborated, some unresolved issues need to be clarified, like pragmatic and sociological expertise for connecting grounded findings, various modes of molding theoretical building blocks and the lack of a unifying low-content matrix. The door is left open for exploration of new topics, also from a cross-disciplinary linguistic viewpoint.