Artificial Intelligence (AI) technology in the educational context, particularly chatbotics, has made significant changes in learning English. This mixed-methods study is intended to explore university students' attitudes toward the potential role of artificial intelligence (AI)-assisted mobile applications. Meanwhile, the role of social presence and human-likeness on learner motivation was examined through a chatbot lens. A total of 256 English as a foreign language (EFL) learners interacted with a chatbot known as Computer Simulation in Educational Communication (CSIEC). Participants' audio-recorded practices, transcriptions, three scales of social presence, learner motivation, and human-likeness, along with a semi-structured focus group interview, were used to collect data, Structural Equation Modeling (SEM) was used for data analysis. Moreover, thematic analysis was adopted to explore the participants' attitudes and perceptions toward using CSIES. The quantitative results indicated that learner motivation was significantly predicted by social presence and human-likeness. The thematic analysis of qualitative data reflected that the attributed descriptions to the CSIEC teacher enhanced learners' motivation, eagerness, and confidence to learn English. The findings of this study may be used to guide future research in using chatbots outside the classroom to serve as learning companions, and educators can utilize them to tailor assessment and feedback procedures.