Abstract
Mistakes and errors are inevitable in learning a second language. Learners of a second language make errors in the process of constructing a new system for the second language. Errors may provide insights into the course of language development. This study aims to investigate, classify, and analyze the different types of errors made by Polish second language learners of Mandarin. I examine 269 errors made by B1 Polish students collected from the TOCFL Learner Corpus and adopt the error taxonomy proposed by Dulay, Burt, and Krashen (1982) and James (2013) with minor revisions. It is found that misselection errors have the highest percentage, 37.9%, followed by omission errors, 35.7%. Redundancy (16.7%) is the third most frequent error type, followed by misordering (7.5%) and mixture (2.2%). Almost three-quarters of the errors are in the misselection and omission categories. Finally, some pedagogical implications are offered.