<p>The Tanka people, colloquially known as the “boat people”, are primarily located in Southeast China. Over time, their transition from a maritime to a land-based lifestyle has significantly influenced the languages they speak, particularly through contact with dominant languages such as Cantonese and Hakka. Despite this, the Tanka language in Hong Kong remains under-researched and is now endangered, with its use rapidly declining. To fill this research gap, this study examined the linguistic interactions between the Tanka language and Cantonese in Hong Kong, focusing on phonological and lexical aspects. The study yielded several key findings. First, a comparative analysis of the phonological systems of the Tanka language and Cantonese revealed striking differences in their rhyme patterns and tone evolution from Middle Chinese. These findings underscore significant phonological distinctions between the two languages. However, despite these differences, Tanka and Cantonese speakers can generally comprehend each other due to a shared linguistic structure. Second, a lexical comparison of the Tanka language, Cantonese, and Mandarin demonstrated a considerable connection between the Tanka language and Cantonese, especially among the younger speakers. This generational influence highlights the impact of Cantonese on the Tanka language. In contrast, the Tanka vocabulary diverged significantly from Mandarin, reflecting a unique linguistic development influenced by its historical and social context, while showing greater convergence with Cantonese due to prolonged contact and shared regional influences. Understanding the interplay between the Tanka language and Cantonese provides valuable insights into the origins of the Tanka people. It also contributes to a broader understanding of the typological characteristics of Sinitic languages in Southeast China.</p>