This chapter presents a quantitative analysis of the frequency and function of you know among L1 speakers of Irish and Australian English and L2 speakers of Polish and Chinese background, residing in Ireland. Results show no significant differences in the frequency of you know in Irish as compared to Australian English. However, you know was highly correlated with I mean in Australian English only. Among the L2 speakers, you know was significantly more frequent among the Polish group as compared to both the Chinese group and the L1 group. Proficiency in English and length of residence were not found to be significant predictors of this trend, although Poles with lower levels of education were found to use more you know. Both L1 groups used more interpersonal functions of you know as compared to the L2 groups, who favored its coherence functions. The findings indicate that the prevalence of you know may contribute to its rapid adoption by L2 speakers, but more close analysis reveals potential challenges for L2 speakers to acquire the full range of functions of discourse–pragmatic markers in spoken discourse. The study shows the importance of examining both frequency and function of discourse–pragmatic markers in language contact situations.