I ought to write a paper with corpus-based analysis of a lexical or morpho-syntactic alternation. In other words, the paper should deal with two (or more) nearly synonymous lexical items or morpho-syntactic patterns (or maybe constructions).
Details: The alternation should be studied from a 'multifactorial' perspective, which means that the effect of grammatical factors, discourse factors and lectal factors on the variation at hand is examined in one overarching model.
What are these alternations? Does anyone know of different examples of these alternations?