This case study investigated the influence of Chinese speakers’ Southwestern dialects, which do not distinguish alveolar nasal sounds /an/, /en/, /in/ and velar nasal /ang/, /eng/, /ing/ sounds in Pinyin, on their English pronunciation in words contain these sounds, as well as whether or not native speakers who speak more standard Mandarin would pronounce more accurate English. Furthermore, the study provides implications of teaching Chinese Southwestern dialects speakers acquiring English sounds that contain alveolar nasal sounds and velar nasal sounds. The implications discussed are anchored in sociocultural theories of Second Language Acquisition, specifically focusing on the Zone of Proximal Development to provide appropriate scaffolding to English learners with Chinese Southwestern dialects background acquiring velar nasal sounds in English. The findings of the study indicated that most of Chinese Southwestern dialects speakers cannot perform velar nasal sounds in Mandarin Chinese and it influences speakers’ performance of velar nasal sounds in English. However, the findings of the study did not conclude that people who speak more standard Mandarin Chinese would speak more accurate English.
Key words: First language; English as a second language; second language acquisition; Chinese dialects; Mandarin; alveolar nasal sounds; velar nasal sounds; Zone of Proximal Development