Nouns are words that directly represent/refer to other things, commonly described as being a person (firefighter, Abe Kōbō, Steve), a place (Mos Burger, Japan, kitchen) or a thing (coffee, book, the theory of relativity).
The line between singular (a dog) and plural (dogs) is not drawn as clearly in Japanese as it is in English. The word for dog, 犬 (いぬ),can refer to one dog or many dogs. Just as with the non-past tense, while the word itself does not change, other words can be used to help make this distinction between one and many clear.
私の犬はちょっと太っている。My dog is a little chubby.
泉の周りに犬がたくさん集まっている。Many dogs are gathered around the fountain.
Nouns can be made plural by using the suffix ～たち, though it is not common to do so.
|男（おとこ）－ man/men||男たち － (a group of) men|
|旅人（たびびと）－ traveler/travelers||旅人たち － (a group of) travelers|
A counter is a unit used to refer to the quantity of any given thing. English sometimes employs counters (two pieces of paper) and sometimes doesn’t (three people). Counters are necessary to count anything in Japanese and there are a plethora of different ones to choose from in order to refer to many different kinds of things. Here are a few very common ones:
#つ → # of (items): 二つの考え (two ideas), 三つのグループ (three groups)
#人 → # (of people): 一人のイタリア人 (one Italian), 兄が二人いる (I have two older brothers)
#度 → # (of times): 一度もない (not even once), 月に二度 (twice per month)
Nominalization is the process of turning other parts of speech into nouns. Nominalized words (such as 走ること or 強さ) function exactly like true nouns (such as バナナ or 犬).
Verbs can be turned into nouns by affixing either こと or の to their dictionary form. Although there are nuances to both, they’re generally interchangeable.
走る (to run) → 走ること・の (running / the act of running)
飲む (to drink) → 飲むこと・の (drinking / the act of drinking)
走ることが好きです。I like running.
ビールを飲むのをやめよう。Stop drinking beer.
Adjectives can be turned into nouns by using ～さ and ～み.
To use ~さ, replace the final い of an い-adjective or the な of a な-adjective with さ.
To use ~み, replace the final い of an い-adjective with み. な-adjectives can not be used with み. Furthermore, the use of ~み in modern Japanese is limited to a very small pool of adjectives.
~さ creates a noun that feels concrete and can be measured, whereas ~み creates an abstract noun: it refers to the nature of something and can carry a poetic feeling.
棚は本の重さで曲がった。The shelf sagged/bent under the weight of the books.
When the soldier gave his opinion, the weight of experience in his words could be readily felt. この椅子には経った月日の重みが染み込まれているのです。
That chair is laden with the weight of bygone years.
Compound nouns are nouns that have been created by putting two words together. Japanese compound nouns may be a combination of two or more kanji (called 熟語・じゅくご) with or without kana. If a word includes kana, the kana typically are placed between two kanji or after the final kanji.
|Noun + Noun||人魚（にんぎょ）
|Noun + nom. adjective||心強さ（こころづよさ）||Reassurance; being heartwarming|
|Adjective + nom. adjective||薄暗さ（うすぐらさ）||Dimness; gloomines|
|Noun + Verb||朝食（ちょうしょく）
The retiring of government officials into lucrative corporate jobs
|Verb + Noun||行き先（行き先)
|Verb + Verb||思い込み（おもいこみ)
|(wrong) impression; assumption