  Although neural network approaches achieve remarkable success on a variety of
NLP tasks, many of them struggle to answer questions that require commonsense
knowledge. We believe the main reason is the lack of commonsense
\mbox{connections} between concepts. To remedy this, we provide a simple and
effective method that leverages external commonsense knowledge base such as
ConceptNet. We pre-train direct and indirect relational functions between
concepts, and show that these pre-trained functions could be easily added to
existing neural network models. Results show that incorporating
commonsense-based function improves the baseline on three question answering
tasks that require commonsense reasoning. Further analysis shows that our
system \mbox{discovers} and leverages useful evidence from an external
commonsense knowledge base, which is missing in existing neural network models
and help derive the correct answer.
