Reduplication, or kata ganda in Malay, is a process of repeating a word, either exactly or with a slight change in tone. It appears quite regularly in Penang Hokkien.
Reduplication is most commonly used to fashion adverbs out of adjectives. Adjectives that are Regular Words form adverbs by reduplicating without tone change.
ban33 slow
ban33-ban33 slowly
Adjectives that are Irregular Words are affected by Tone Sandhi when they are reduplicated. These adjectives form adverbs by changing the tone of the first word (or morpheme) to the Modified Form, while the second word remains in the Basic Form.
khuai3 quick
khuai1-khuai3 quickly
Reduplication can also be used to express a diminutive quality of the adjective, similar to "-ish" in English.
ang2 red
ang3-ang2 reddish
tam2 wet
tam3-tam2 slightly wet, wettish
The resulting reduplicated word can function as both adverb and adjective. Where they precede the noun they modify, the possessive particle -eh3 is attached to them.
Ee1-eh3 bin33 ang3-ang2.
His face is reddish. (adjective)
Ee1-eh3 ang3-ang2-eh3 bin33 enee2.
His reddishface is round. (adjective)
Ee1 chat3 heh1-leh1 piak3 ang2.
He painted the wall red. (adverb).
Heh1-leh1 khor3 tam2.
The pants are wet. (adjective)
Heh1-leh1 khor3 kokh1 si33 tam3-tam2.
The pants are still a bit wet. (adjective)