Reduplication means to duplicate a word in order to modify its meaning.

In Lugamun, adjectives and adverbs can be reduplicated in order to make them more intense – this is similar to placing ingi ‘very’’ before them.

hau – good
hau hau – very good, excellent

mali – small
mali mali – very small, tiny

This meaning also applies when adjectives are used as verbs:

Ta ruma (xi) gran gran! – That house is (really) huge!

If other verbs are reduplicated, this indicates an activity going on for a long time:

Ya li nulis nulis [until] nait van. – He/She wrote and wrote until late at night.

Rationale: According to WALS (ch. 27), most languages use reduplication for some semantic or grammatical purposes. WALS doesn’t include a detailed study of what these purposes are, but according to APiCs (ch. 26), pidgins and creole languages most typically use it for iconic functions such as intensity (making a quality stronger) or iteration (indicating that a action takes place repeatedly or for a long time). We use it for these purposes as well. Cases of reduplication changing a word class are less frequent, but this is still the second most common function. We use it for this purpose too (see the next section).

Another use of reduplication is the formation of adverbs from short prepositions. In these cases, the resulting adverb is written as a single word.

gen – (together) with
gengen – together
su – under, below
susu – down, below, downward(s)

Example:

Ona li go gen man. – The woman went with the man.
Ona va man li go gengen. – The woman and the man went together.

Reduplication is only used with short prepositions that have just a single syllable. With longer prepositions, the result of reduplication would be a bit heavy (four syllables or more). Therefore ku is used to derive adverbs from prepositions with two or more syllables (just as from adjectives).

estra – extra-, outside (prefix + preposition)
ku estra – outside, outward (adverb)