The world is full of things. There are big and small things, simple and more complex things, real and fake things, useful and useless things. In Japanese, these things are all 物 (mono, also read as butsu or motsu in compounds), and this word has some quite surprising qualities.
Let’s start with things at home, where they may actually be quite a nuisance. A room in which 物が多い (mono ga ōi, there are many things) feels rather tense and disorderly. A 物置 (monooki, storeroom) can help a great deal here, unless it’s already overflowing with stuff. If that’s the case, there’s only one cure to this mono-mania: 物を捨てろ (mono o sutero, throw things away)!
The most convenient thing about 物 is that it is often used to form generic terms that capture a whole bunch of quite different things. Just think of 買い物 (kaimono) for anything one might possibly shop, 建物 (tatemono) as a superordinate term for all conceivable types of buildings, or 乗り物 (norimono) to denote things vehicular, from horse-drawn carriages to roller coasters.
And there are more of these “thing-things”: 金物 (kanamono, hardware) and 織物 (orimono, textiles), 荷物 (nimotsu, baggage) and 貨物 (kamotsu, freight), 洗濯物 (sentakumono, laundry) and 洗い物 (araimono, dirty dishes), 郵便物 (yūbinbutsu, mail) and 印刷物 (insatsubutsu, printed matter), 忘れ物 (wasuremono, things left behind) and 落し物 (otoshimono, things lost), もらい物 (moraimono, gifts received) and 贈り物 (okurimono, gifts given), and of course 食べ物 (tabemono, food) and 飲み物 (nomimono, beverages).
Perhaps somewhat counterintuitively, 物 is also commonly used to refer to living things — known in Japanese as 生き物 (ikimono) or 生物 (seibutsu), as in 生物学 (seibutsugaku, biology). These can be further subdivided into 植物 (shokubutsu, plants) and 動物 (dōbutsu, animals). The latter includes 万物の霊長 (banbutsu no reichō, the lords of creation), which literally can be translated as “the primates of all things,” but in fact refers to humans. Yes, we are a type of thing too, as witnessed by terms such as 人物 (jinbutsu, person, character) and 大物 (ōmono, important person, influential figure).
Yet another thing about the thing in Japanese is that it can attach to adjectives and adjective-like expressions, for no apparent reason except to give them a more “material” touch. Best known, perhaps, are 物足りない (monotarinai, unsatisfactory) and ものすごい (monosugoi, frightful, terrific). Other examples are 物憂い (monoui, languid), 物悲しい (monoganashii, sad, plaintive), 物珍しい (monomezurashii, strange, curious), 物柔らか (monoyawaraka, soft-spoken, gentle) and 物堅い (monogatai, faithful, reliable), as well as 物騒がしい (monosawagashii, noisy) and 物静か (monoshizuka, quiet). Note that this pattern is not productive in a linguistic sense, meaning it is confined to a handful of combinations and you cannot mono-fy just any adjective.
But most enigmatic is what happens when the thing goes grammar — when mono is used in grammatical constructions that no longer seem to have much to do with “things” whatsoever. In such instances, it is frequently clipped into mon, as in the somewhat resigned observation そういうもんか (Sō iu mon ka, “So that’s how it is”) and its standard reply, そういうもんだ (Sō iu mon da, “That’s how it is”).
It is difficult to summarize the various things もん does when it suddenly shows up like this towards the end of a sentence. Largely simplifying, it seems to invoke some higher-order principle of generality or common sense, no matter how haphazard or absurd the contents of what is actually being said may be.
A basic distinction can be made with respect to whether もん comes before or after the copula verb (だ, da) in a sentence. If mon comes first, the reference to some objective truth may still be scrutable. Take that common saying: いくら食べても腹は減るもんだ (Ikura tabete mo hara wa heru mon da, “No matter how much you eat, you will get hungry again”).
However, when もん is inserted after the だ, it is normally the case that the logic of the argument is heavily skewed toward the speaker. “Like it or not, that’s how I see it” is the meta-message of もん here. This effect can be further enhanced by adding the conjunction だって (datte, because, but) at the beginning of the sentence, as in だって嫌いだもん (Datte kirai da mon, “But I just hate it!”).
As these examples show, the thing in Japanese has a number of amazing metaphorical and metaphysical properties that do far more than just mess up your room. Though it’s a good idea to get rid of things every now and then, it would be impossible to live in a world without them.