Abstract Depending on the theory of language employed, the paradigmatic and lexical variation associated with a given composite form-meaning pair is treated in different ways. First, variation can be treated as independent of the constructional semantics, an approach typical of modular theories. Second, paradigmatic variation can be considered indicative of constructional semantics; its variation constituting networks of closely related families of constructions. This is a common approach in construction grammar. Third, there exists a trend in cognitive linguistics and construction grammar to treat grammatical constructions as non-discrete emergent clusters of many-to-many form-meaning mappings. This study explores the possibility of extending current methods for quantitatively modelling construction grammar to an approach that does not assume discrete grammatical constructions. The speaker choice examined consists of the English future constructions will and BE going to and their use in contemporary informal British English. The constructions are examined with the behavioural profile approach. Three different regression modelling methods are applied to the grammatical alternations, each operationalizing one of the theoretical assumptions. While the results show that all three approaches are feasible and comparable in predictive accuracy, model interpretation becomes increasingly difficult with added complexity.