  In this paper, we propose Tutoring bot, a generative chatbot trained on a
large scale of tutor-student conversations for English-language learning. To
mimic a human tutor's behavior in language education, the tutor bot leverages
diverse educational instructions and grounds to each instruction as additional
input context for the tutor response generation. As a single instruction
generally involves multiple dialogue turns to give the student sufficient
speaking practice, the tutor bot is required to monitor and capture when the
current instruction should be kept or switched to the next instruction. For
that, the tutor bot is learned to not only generate responses but also infer
its teaching action and progress on the current conversation simultaneously by
a multi-task learning scheme. Our Tutoring bot is deployed under a
non-commercial use license at https://tutoringai.com.
