The aim of this paper is to examine the role of language dominance in loanword phonology. It is investigated how onset clusters in loanwords are integrated into Turkish by two groups: English-Turkish bilinguals in Turkey and Swedish-Turkish bilinguals in Sweden. It is hypothesised that the bilinguals in Sweden will display significantly higher rates of cluster adoption because Turkish is not the dominant language there.

The data were collected through an oral loanword elicitation task, a text recitation task in the second languages and a questionnaire on language proficiency and use.

The study had 53 participants (24 in Turkey and 29 in Sweden). The material consisted of 29 loanwords from English and French, and of 50 structurally comparable words in the bilinguals’ second languages. The data were analysed auditively by the author and subjected to an interrater reliability test.

The results confirmed the hypothesis as the bilinguals in Sweden displayed significantly higher cluster adoption rates. The difference between the groups’ medians was 36.5 percentage points. Furthermore, it was shown that in individual speakers the combination of accurate second-language pronunciation, and clearly higher proficiency in the second language (corresponding to the donor language) compared to the L1 (i.e. the recipient language) guaranteed very high cluster adoption rates.

This paper provides the first rigorous quantitative proof for the theoretical assumption that accurate pronunciation is not sufficient for structural adoption in loanword phonology but needs to be complemented with sociolinguistic variables. Furthermore, it demonstrates in greater detail than before how societal and individual dominance are connected and through which channels they impact loanword integration.

Self-reported relative proficiency in the donor language was shown to be a powerful predictor of the sociolinguistic incentive to adopt and could therefore be used as a quick and reliable alternative to elaborate and time-consuming attitude investigations in loanword phonology.