～わけだ (that's why / no wonder)

Japanese Grammar Basic Japanese ★★★★ 4/5 neutral わけだwake da
Reading わけだ
Romaji wake da
Formation Verb (plain form) + わけだ / い-Adj + わけだ / な-Adj + な + わけだ / Noun + の/な + わけだ
Kanji breakdown 訳 — reason, meaning, logic, translation

Meaning

An expression used when the speaker reaches a logical conclusion through reasoning or deduction. It conveys the meaning of 'that means,' 'no wonder,' or 'so that's why.'

わけだ (from 訳 meaning 'reason' or 'logic') is used when the speaker arrives at a conclusion based on available information or reasoning. It differs from はずだ (expectation based on evidence) and ものだ (general truth). The speaker connects known facts to reach a natural, logical conclusion. For example, upon learning someone studied in France: フランスに住んでいたのか。フランス語が上手なわけだ (So you lived in France. No wonder your French is good). The negative わけではない means 'it doesn't mean that' or 'it's not the case that,' used to correct assumptions. わけがない means 'there's no way that.' In casual speech, わけ often contracts to わけ with rising intonation for questioning.

Examples

  1. 毎日練習しているから、上手になるわけだ。 Since you practice every day, no wonder you've gotten good.
  2. 二時間も歩いたのか。疲れたわけだ。 You walked for two hours? No wonder you're tired.
  3. 値段が安いわけではない。 It's not that the price is cheap.

Usage Guide

Context: spoken, written, everyday

Tone: analytical

Do Say

  • 三年も日本にいたのか。日本語が話せるわけだ。
  • 全員が反対したわけではありません。
  • なるほど、それで遅刻したわけか。

Don't Say

  • 明日は雨が降るわけだ。(わけだ is for conclusions drawn from known facts, not weather predictions without supporting evidence) → 天気予報によると、明日は雨が降るそうだ。
  • お腹が空いたわけだ。(Simply being hungry is a direct feeling, not a logical deduction — わけだ needs a reasoning chain) → 朝ごはんを食べなかったから、お腹が空いたわけだ。

Origin & History

わけ derives from the noun 訳 (wake), meaning 'reason,' 'meaning,' or 'logic.' Combined with だ, it literally says 'it is the reason/logic that...' — marking a statement as a logical deduction.

Cultural Context

Generation: All ages

Social background: Universal

Related Phrases

～こと (intangible thing) A formal noun that refers to an abstract, intangible thing such as an event, fact, experience, or matter. It contrasts with もの, which typically refers to tangible objects. ～こと (nominalizer) A nominalizer that converts a verb phrase or clause into a noun phrase. It indicates a relatively objective or emotionally detached perspective compared to the nominalizer の. ～ことがある (experience) Used with the past tense of a verb to express that someone has had the experience of doing something at least once. It is equivalent to 'have done' or 'have experienced' in English. ～という (called / that says) A phrase that marks information identifying, naming, or explaining the noun that follows. It connects a descriptive clause or name to a noun, equivalent to 'called,' 'named,' or 'that says.' ～は～が (topic has attribute) A construction that relates a non-controllable state, attribute, or ability to a topic. The は marks the overall topic, while が marks the specific subject of the attribute or state being described. 連体修飾節 (Relative Clause) A clause that modifies a noun by placing a verb, adjective, or clause directly before the noun without a relative pronoun. Japanese relative clauses precede the noun they modify. ～ことがある (sometimes) Used with the dictionary form of a verb to express that something happens occasionally or from time to time. It conveys the idea that an event occurs sometimes but not regularly. ～として (as / in the capacity of) A compound particle that indicates the capacity, role, function, or status in which someone or something acts. It is equivalent to 'as' or 'in the role of' in English.
Practice this on WordLoci

Flashcards, quizzes, audio pronunciation and spaced repetition