  Conversational practice, while crucial for all language learners, can be
challenging to get enough of and very expensive. Chatbots are computer programs
developed to engage in conversations with humans. They are designed as software
avatars with limited, but growing conversational capability. The most natural
and potentially powerful application of chatbots is in line with their
fundamental nature - language practice. However, their role and outcomes within
(in)formal language learning are currently tangential at best. Existing
research in the area has generally focused on chatbots' comprehensibility and
the motivation they inspire in their users. In this paper, we provide an
overview of the chatbots for learning languages, critically analyze existing
approaches, and discuss the major challenges for future work.
