Computer-assisted language learning (CALL) provides an effective learning environment so that students can practice in an interactive manner using multi-media content, either with the supervision of teachers or on their own pace in self-learning. The advancement of speech and language technologies has opened new perspectives on CALL systems, such as automatic pronunciation assessment and simulated conversational-style lessons. CALL is also regarded as one of new and promising applications of speech analysis, recognition and synthesis. CALL covers a variety of aspects including segmental, prosodic and lexical features. Modeling non-native speech to correctly segment/recognize utterances while detecting errors included in them poses a number of challenges in speech processing. Assessing intelligibility of non-native speech or proficiency of non-native speakers is also an important issue. In this tutorial, we will give an overview on these issues and current solutions. The tutorial is mainly targeted for speech researchers and engineers interested in CALL, but also for those engaged in language teaching or learning technology.