A computer assisted pronunciation training (CAPT) system is implemented for native Korean speakers who are learning American English. The CAPT system is designed to help a Korean adult learner improve his/her production and perception of American English front vowels (/i, I, ɛ, æ/) since these vowels are the most difficult for Korean learners due to the different phonetic systems of the two languages. The CAPT system provides a learner a learning session mimicking a live interaction between teacher and student as well as a practice session triggering a learner’s interest in continued practice. Pedagogically meaningful activities such as listen-and-repeat, minimal-pair-comparison, target-sound-isolation, and record-and-play are utilized in the learning session. During the learning session, the CAPT system analyzes a monosyllabic word including one of the target front vowels spoken by a learner and gives instantaneous personalized feedback. During the practice session, the CAPT system provides real-time games that are fun but also provide the necessary perception and articulation practice.