The present study aims at analysing the Czech L1 and Russian L1 subcorpora of the International Corpus of Learner Finnish. The study focuses on morphosyntactic, phraseological and verb choice errors found in texts rated at level B1 according to the Common European Framework of Reference for Languages, with a view to uncovering converging and diverging trends in error frequency and type.
The results indicate that the most common error types in both subcorpora concern adverbial case-marking and phraseology. The results also point to differences in error frequency in subject case-marking and syntactic structure on the one hand (these errors were found to be significantly more frequent in the Czech L1 subcorpus) and verb choice on the other hand (these errors were found to be more frequent in the Russian L1 subcorpus).
The present research confirms previous findings of studies of Finnish as a Second and Foreign Language, such as the prominence of time expression errors, the high frequency of phraseological errors and the overrepresentation of the nominative case in object and predicative case-marking and of the A-infinitive in verb plus verb constructions. The overrepresentation of the nominative case and of the A-infinitive in learners' texts point to a simplification tendency typical of learner language, while the higher frequency of verb choice errors in the Russian L1 subcorpus indicates that task type influences error frequency and type, since the Russian L1 subcorpus, unlike the Czech L1 subcorpus, includes translation tasks.