本文以優選理論（Optimality Theory）分析東勢客語中涉及特殊變調的三種重疊型式，包含AB(C)AB(C)型式、AAA型式、以及AAAA型式。本文指出，這三類重疊型式之變調現象看似十分不同，卻都內含一個浮游聲調（floating tone），且該聲調均出現在重疊部份（reduplicant）之右側。此外，AAA型式和AAAA型式另外涉及了特定聲調組合。本文指出，這種現象和文獻中常見涉及特定音段的重疊現象十分相似，出現的特定成份也都屬於較為無標的聲調。聲調。

This paper investigates the special tone sandhi phenomena in the reduplication patterns of AB(C)AB(C), AAA, and AAAA in Dongshi Hakka. These patterns are notable in that they involve tone sandhi patterns that are different from those found in non-reduplications.Within the constraint-based theory of OT, this paper shows that although the tonal alternations observed in the different reduplication patterns are distinct from one another, they are all accompanied with a floating high tone which contributes greatly to the special patterns associated with tone sandhi. In addition to the existence of a floating high tone, AAA reduplication and AAAA reduplication also surface with fixed tonal melodies. It is shown that the fixed tonal melodies in the two patterns of reduplication actually resemble the common phenomena of fixed segmentism in reduplication and are driven by markedness requirements.