The use of English as a global language has led to a growing number of non-native English speakers, including Chinese learners, who speak English with an accent influenced by their first language. This phenomenon can be explained by the mutual exclusivity assumption, which means that our first language will interfere with the second language acquisition. This study examines the role of the English phoneme/r/in the accented English of Chinese learners. The research investigates how Chinese learners perceive, produce, and acquire /r/in English and the challenges they face in mastering this sound. The study draws on existing research on the mutual exclusivity effect, second language acquisition, and phonology employing a qualitative method to analyze data collected from Chinese learners of English with the help of Praat. The findings reveal that Chinese learners encounter difficulties with /r/ due to the absence or different phonetic realization of this sound in their native language. These learners often struggle with both the perception and production of /r/, leading to various types of mispronunciation. The study also identifies factors that contribute to the challenges faced by Chinese learners in acquiring /r/, including the influence of their first language, the age of acquisition, and the exposure to English input. Furthermore, the study highlights the importance of teaching strategies that target the specific needs of Chinese learners in mastering/r/and improving their overall English pronunciation.