Explanatory grammar refers to the conceptual relations through which an explanatory approach identifies its questions, distinguishes relevant phenomena, and formulates candidate explanations.
In APS, this grammar begins from living organisation rather than from a privileged list of entities or causal levels. Agency, Process, and Scale provide complementary analytic projections of one viability-oriented, constraint-closed organisation: Agency concerns what living systems do, Process concerns how organisational continuity is maintained through change, and Scale concerns where persistence is organised across spatial and temporal extents.
Explanatory grammar can therefore shape what an inquiry makes salient without determining in advance what counts as an adequate explanation. APS may direct attention toward organisational dependencies, viability, continuity, constraints, and relations across spatial and temporal extents, but identifying those features does not by itself establish explanatory gain.
Whether an APS account contributes additional explanation must instead be assessed relative to a specified explanandum and the relevant established comparator. A mechanistic, evolutionary, developmental, ecological, or other explanation is not incomplete merely because it does not employ APS terminology or all three analytic projections. Where APS identifies a relevant dependency not captured by the comparator, it may add explanatory value; where it merely redescribes what is already explained, it does not.
In brief: explanatory grammar helps organise what an explanatory approach asks and makes salient; comparative assessment determines what the resulting explanation actually contributes.