The positioning of concessive adverbial clauses in English: assessing the importance of discourse-pragmatic and processing-based constraints

English permits adverbial subordinate clauses to be placed either before or after their associated main clause. Previous research has shown that the positioning is conditioned by various factors from the domains of semantics, discourse pragmatics and language processing. With the exception of Diessel (2008), these factors have never been investigated in concert, which makes it difficult to understand their relative importance. Diessel's study, however, discusses only temporal constructions and identifies iconicity of sequence as the strongest predictor of clause position. Since this explanation is, in principle, unavailable for other types of subordinate clauses, the generalizability of Diessel's findings is somewhat limited. The present study offers a multifactorial analysis of 2,000 concessive constructions from the written part of the BNC and assesses the variable importance of six factors for the ordering choice, showing that semantic and discourse-pragmatic factors are much stronger predictors of clause position than processing-based, weight-related ones. On a methodological note, the study proposes that random forests using conditional inference trees constitute the preferred tool for the general type of problem investigated here.