An Annotated Error Corpus for Esperanto

This paper presents and evaluates a new multi-genre error corpus for (written) Esperanto, EspEraro, building on both learner, news and internet data and covering both ordinary spelling errors and real-word errors such as grammatical and word choice errors. Because the corpus has been annotated not only for errors, error types and corrections, but also with Constraint Grammar (CG) tags for part-of-speech, inflection, affixation, syntactic function, dependency and semantic class, it allows users to linguistically contextualize errors and to craft and test CG rules aiming at the recognition and/or correction of the various error types covered in the corpus. The resource was originally created for regression-testing a newly developed spell- and grammar checker, and contains about 75,000 tokens (~ 4,000 sentences), with 3,330 tokens annotated for one or more errors and a combined correction suggestion. We discuss the different error types and evaluate their weight in the corpus. Where relevant, we explain the role of Constraint Grammar (CG) in the identification and correction of the individual error types.