3D virtual worlds are promising for immersive learning in English as a Foreign Language (EFL). Unlike English as a Second Language (ESL), EFL typically takes place in the learners' home countries, and the potential of the language is limited by geography. Although learning contexts where English is spoken is important, in most EFL courses at the college level, EFL is taught by acquiring vocabularies, grammar and pragmatic features without contextual immersion. In this study, an immersive English learning environment in a 3D virtual world, OpenSimulator, was developed with two key learning artifacts, chatbot and time machine. A single-factor, independent measures design was used to examines learners' presence under four learning conditions: virtual learning environment without digital learning artifacts (VE), virtual learning environment with chatbot (VEC), virtual learning environment with time machine (VETM) and virtual learning environment with chatbot and time machine (VECTM). Three research questions emerging from the four learning conditions form the backbone of this study: (1) Does chatbot increase language learners' presence in the immersive virtual English learning environment? (2) Does time machine increase language learners' presence in the immersive virtual English learning environment? (3) Does the combined use of chatbot and time machine increase presence more than either learning artifact alone? The experimental results indicate that the chatbot and time machine increase the learners' sense of immersion and presence. Best design practices should address how immersion and presence can be integrated into affordances of virtual worlds.