  This paper reports on progress towards building an online language learning
tool to provide learners with conversational experience by using dialog systems
as conversation practice partners. Our system can adapt to users' language
proficiency on the fly. We also provide automatic grammar error feedback to
help users learn from their mistakes. According to our first adopters, our
system is entertaining and useful. Furthermore, we will provide the learning
technology community a large-scale conversation dataset on language learning
and grammar correction. Our next step is to make our system more adaptive to
user profile information by using reinforcement learning algorithms.
