The Meaning of kau [買う] In Japanese

買う
かう
Romaji: kau N5

What does 買う mean?

Translation and Meaning

to buy, purchase

Definition

What does 買う mean? It denotes the act of obtaining goods or services by paying money; a transitive verb used to express acquiring something in exchange for money, typically referring to consumer purchases.

Type

verb (五段動詞)

Stroke Order

Meanings

  • Basic purchase: acquiring a tangible item or service for oneself or someone else.
  • Broader shopping context: used in everyday commerce, including online purchases.
  • Figurative or extended uses: can imply procuring or securing things like tickets or opportunities in certain contexts.

Etymology

Phono-semantic compound with semantic 貝 (shell money, commerce) indicating the buy/sell domain, and a phonetic cue guiding the modern kun reading kau; the on’yomi reading bai appears in compounds under Chinese influence.

Origin

Old Japanese evidence shows 買う as a basic verb for exchanging money for goods, reflecting the emergence of market exchange as coinage and merchant networks expanded in classical periods; the concept solidified through Heian to Edo-era commerce and everyday shopping practice.

Composition

  • 貝 radical: money, shells used as currency
  • 買: semantic core of purchase; phonetic cue suggests sound
  • う: okurigana marking the verb inflection

Usage

Used as a transitive verb with a direct object marked by を; polite form 買います, past 買った; common in shopping contexts, both in physical stores and online; also appears in compounds like 買い替える to replace by buying anew and 買い物をする to go shopping.
💡 Tips
Mnemonic: picture shell money exchanging hands at a market to buy a desired item; the 貝 radical signals money, guiding you to the meaning of purchase every time you see the kanji.

Variations

  • 購⼊する (kounyuu suru) — to purchase; romaji: kounyuu suru
  • 買い物をする (kaimono o suru) — to go shopping; romaji: kaimono o suru
  • 仕入れる (shiireru) — to stock/procure; romaji: shiireru
  • 売る (uru) — to sell; romaji: uru

Example Phrases

  • スーパーで原料を買うときは賞味期限を確認する
    Sūpā de genryō o kau toki wa shōmi kigen o kakunin suru.
    When buying raw materials at the supermarket, check the expiration date.
    Lista:
    • スーパー (Sūpā) – supermarket
    • で (de) – at
    • 原料 (genryō) – raw materials
    • を (o) – object marker
    • 買うとき (kau toki) – when buying
    • は (wa) – topic marker
    • 賞味期限 (shōmi kigen) – expiration date
    • を (o) – object marker
    • 確認する (kakunin suru) – to check
    In this sentence, 「原料」 means ‘raw materials/ingredients’ and is the object of 買う. 「賞味期限」 refers to the expiration date.
  • 盆地の朝 市場で 新鮮な 野菜を 買う。
    Bonchi no asa ichiba de shinsen na yasai o kau.
    In the basin’s morning, I buy fresh vegetables at the market.
    Lista:
    • 盆地の朝 (Bonchi no asa) – basin’s morning
    • 市場で (ichiba de) – at the market
    • 新鮮な (shinsen na) – fresh
    • 野菜を (yasai o) – vegetables
    • 買う (kau) – to buy
    Core grammar: の links a noun to another noun to create a time phrase, as in 「盆地の朝」; it also uses で after 市場 to indicate location.
  • 会社へ いく 前に コーヒーを 買う
    kaisha e iku mae ni koohii o kau
    Before going to the company, buy coffee.
    Lista:
    • 会社へ (kaisha e) – to the company
    • いく (iku) – go
    • 前に (mae ni) – before
    • コーヒーを (koohii o) – coffee
    • 買う (kau) – to buy
    Here 「いく」 is the dictionary form meaning ‘to go’, used with 「へ」 to indicate the destination; 「前に」 marks ‘before’ doing the next action.
  • 今夜はスーパーで晩ごはんを買うつもりだ。
    Kon’ya wa sūpā de bangohan o kau tsumori da.
    I’m planning to buy dinner at the supermarket tonight.
    Lista:
    • 今夜は (kon’ya wa) – tonight
    • スーパーで (sūpā de) – at the supermarket
    • 晩ごはんを (bangohan o) – dinner (object)
    • 買う (kau) – buy
    • つもりだ (tsumori da) – intend to
    Core grammar: use 「買う」 with を to mark the object; 「つもりだ」 expresses intention.
  • 壊れた電球を取り替えるために新しい電球を買う。
    Kowareta denkyū o torikaeru tame ni atarashii denkyū o kau.
    I buy a new light bulb to replace the broken one.
    Lista:
    • 壊れた (kowareta) – broken
    • 電球を (denkyū o) – light bulb
    • 取り替える (torikaeru) – to replace
    • ために (tame ni) – in order to
    • 新しい (atarashii) – new
    • 電球を (denkyū o) – light bulb
    • 買う (kau) – to buy
    Core grammar: the verb 「取り替える」 means ‘to replace’ and is transitive with the object marked by 「を」; 「ために」 marks purpose.
買う