The article is connected to the project "DiAsPol250" in which Polish is compared to Czech and Russian from the perspective of the evolution of their aspect systems (http://www.diaspol.uw.edu.pl/). We make use of existing synchronic and diachronic electronic corpora and are building a corpus of our own with annotated aspect pairs; we also create a database of aspect triplets whose role we consider as particularly important for the system.
We want to assess which changes have occurred since the mid-18th century in prefixing and suffixing strategies of verb stems, both in general and by comparing particular prefixes and suffixes, especially so-called natural (vs. specialized) prefixes (according to Janda et al., 2013). The article supplies a sketch of the general premises of the project, and it summarizes our experience with existing large corpora and databases which we have been employing.
We also present a case study in order to demonstrate a procedure designed to compare the distribution of the Czech prefix z- in triplets and in the corpus. This procedure is meant to check more general tendencies; it also illustrates why electronic corpora cannot be replaced in research on distributional properties and why their role does not consist simply in providing examples for the illustration of hypotheses.