Reduplication

Duples

khuikhuy 🔊 (khuy+khuy; 開開; very open)
khiuxkhiu 🔊 (QQ/糗; chewy)
lauxkhokkhog, peh-phauphaw (BPP), suytangtafng, etc. (Online Abbreviations)
tataf 🔊 (taf+taf; very dry)

Triplication

In Taiwanese, triplication refers to repeating a syllable three times for emphasis. For example, "aang" means "red". Something extremely red is "aarng'ang'aang" (紅紅紅). Generally, the first syllable must undergo tone change to the rare rising tone (#6).

kaao'kauxkau
zeerng'zexngzeng
kiirm'kimkym
khuiie'khuikhuy 開開開
thoor'thothoo
kao'kaokaux
sirn'sirnsixn
kof'kofkor
lefng'lefnglerng
seek'segsek
took'togtok
siaap'siapsiab
siip'sipsib