Number
Number
Indonesian grammar does not regularly mark plurals. In Indonesian, to change a singular into a plural one either repeats the word or adds para before it (the latter for living things only); for example, "students" can be either murid-murid or para murid. Plurals are rarely used in Indonesian, especially in informal parlance. Reduplication is often mentioned as the formal way to express the plural form of nouns in Indonesian; however, in informal daily discourse, speakers of Indonesian usually use other methods to indicate the concept of something being "more than one". Reduplication may also indicate the conditions of variety and diversity as well, and not simply plurality.
Reduplication is commonly used to emphasise plurality; however, reduplication has many other functions. For example, orang-orang means "(all the) people", but orang-orangan means "scarecrow". Similarly, while hati means "heart" or "liver", hati-hati is a verb meaning "to be careful". Also, not all reduplicated words are inherently plural, such as orang-orangan "scarecrow/scarecrows", biri-biri "a/some sheep" and kupu-kupu "butterfly/butterflies". Some reduplication is rhyming rather than exact, as in sayur-mayur "(all sorts of) vegetables".
Distributive affixes derive mass nouns that are effectively plural: pohon "tree", pepohonan "flora, trees"; rumah "house", perumahan "housing, houses"; gunung "mountain", pegunungan "mountain range, mountains".
Quantity words come before the noun: seribu orang "a thousand people", beberapa pegunungan "a series of mountain ranges", beberapa kupu-kupu "some butterflies".
Plural in Indonesian serves just to explicitly mention the number of objects in sentence. For example, Ani membeli satu kilo mangga (Ani buys one kilogram of mangoes). In this case, "mangoes", which is plural, is not said as mangga-mangga because the plurality is implicit: the amount a kilogram means more than one mango. So, as it is logically, one does not change the singular into the plural form, because it is not necessary and considered a pleonasm (in Indonesian often called pemborosan kata).