This research aims to develop collaborative language learning systems based on social and cognitive presence for learning settings out of class, and evaluate their effects on learning attitude and performance. The main purpose of this system is focusing on the building of a learning community, therefore the Community of Inquiry (CoI) framework suggested by Garrison, Anderson, and Archer (2000) was considered to design this system. This system "C 4 " (spelled out as C quad) consists of three functions: chatbot, constitutive chat, and contribution visualization for the enhancement of social and cognitive presence. In this paper, we explain system design and architecture, and discuss future work.