https://doi.org/10.1177/1367006919844032 International Journal of Bilingualism 1–13 © The Author(s) 2019 Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/1367006919844032 journals.sagepub.com/home/ijb The influence of native English- speaking environment on Akan- English bilinguals’ production of English inter-dental fricatives Felix Kpogo Boston University, USA Virginia C Mueller Gathercole Florida International University, USA Abstract Aims and Objectives: This study examined how age of acquisition, immersion in a native English-speaking environment, and phonological environment influence Akan-English bilinguals’ production of English inter-dental fricatives. Design/Methodology: Forty-five Akan-English bilinguals who immigrated to the USA between the ages of 10 and 64 participated. English inter-dental fricatives occurring in word-initial, intervocalic, and word-final positions were elicited through a production task using sentence frames. Accuracy of production was analyzed relative to age of acquisition, relative length of immersion, and phonological environment. Findings/Conclusion: Performance was better overall on the voiceless than the voiced inter- dental, but the phonological environment mattered: performance was at ceiling for both in the medial position, but less good in the initial and final positions. Early age of acquisition conspired with length of residence in the USA to foster better production for both sounds. However, substitutions for target segments were still observed in the most fluent speakers. These results indicate that in determining speakers’ proficiency in the second language, we must consider all of these factors—phonological environment, age of acquisition, and length of stay—together to gain a comprehensive picture of development. Originality: Few studies have examined Ghanaian speakers’ English, even though English is the official language of Ghana. Further, previous studies on second-language speakers’ abilities with inter-dental fricatives have largely focused on word-initial environments. The present study reveals that distinct phonological environments may not show the same effect. Here, speakers were particularly accurate in intervocalic positions. Significance: This study contributes to theoretical debates concerning the roles of input and age of acquisition for second-language learning. It also provides insights on some of the possible hurdles that second-language learners face as they strive to acquire additional languages, which can assist second-language teachers in designing appropriate methodologies to help learners. Corresponding author: Felix Kpogo, Boston University, 621 Commonwealth Avenue, Boston MA 02215, USA. Email: fkpog001@bu.edu 844032IJB 0 0 10.1177/1367006919844032International Journal of BilingualismKpogo and Gathercole research-article 2019 Original Article