わけだ Japanese Grammar Lesson
Grammar Type: Phrase
Essential Meaning: No wonder / So that means / I take it that / So that’s the reason why
Construction:
- (Verb / い-Adjective) informal + わけだ
- E.g. 話すわけだ [I take it that X speaks / No wonder X speaks]
- E.g. 食べるわけだ [I take it that X eats / No wonder X eats]
- E.g. 高いわけだ [I take it that X is expensive / No wonder X is expensive]
- な-Adjective Stem + わけだ
- E.g. 静かなわけだ [I take it that X is quiet / No wonder X is quiet]
- Noun + [という / だった] + わけだ
- E.g. 先生というわけだ [I take it that X is a teacher / No wonder X is a teacher]
Notes:
- On its own, わけ is a noun that means “Reason“.
- E.g. 会社をやめたそうですが、そのわけを聞かせてください。[I heard that you quit the company…Please tell me the reason.]
- The phrase わけだ expresses the speaker’s judgement, conclusion, or deduction based on some prior verbal context. In other words, わけだ translates roughly to “No wonder“, “So that means“, or “So for that reason“. The て-Form of わけだ is わけで.
- E.g. お母さんと二人だけですか。そういうわけで結婚できないんですか。[Is it only you and your mother? So that means you haven’t found a spouse, right?] In this example, the verbal context is that the hearer is alone with his mother. The speaker uses this context to make the deduction that the hearer is unmarried.
- E.g. 明日試験ですか。じゃあ、こんばん忙しいわけですね。[Do you have a test tomorrow? I take it that you’ll be busy tonight for that reason.] In this example, the spoken verbal context is that the hearer has a test tomorrow. The speaker goes on to use this evidence as the basis for the conclusion that the hearer must be busy tonight.
- E.g. 毎日プールで泳いでいるんですか。丈夫なわけですね。[Are you swimming in the pool every day? No wonder you’re strong.] In this example, the spoken verbal context is that the hearer swims in the pool every day. Based on this evidence, the speaker concludes that swimming is the reason why the hearer is so strong.
- わけだ is somewhat similar to はずだ. The main differences are that (1) はずだ only indicates the speaker’s expectation (rather than their judgement), and (2) はずだ does not require prior verbal context.
- E.g. 明日は授業がないはずですよ。[I expect that there won’t be class tomorrow.]
- E.g. あの人は若いはずですよ。[I expect that that person is young.]
Example Sentences:
毎日三時間も日本語を勉強しているんですか。よくできるわけですね。[You’re studying Japanese for 3 hours every day? No wonder you’re so good.]
明日試験ですか。じゃあ、こんばん忙しいわけですね。[Do you have a test tomorrow? I take it that you’ll be busy tonight for that reason.]
スミスさんは十年間もテニスをしたのだから上手なわけだ。[Mr. Smith played tennis for as long as 10 years, so I take it that he’s pretty good.]
A: 来月から4ヶ月フランスに行きます。 B: すると、六月に帰ってくるわけですね。[A: Next month, I’m going to France for 4 months. B: If you do that, I take it that you’ll be back in June?]
毎日プールで泳いでいるんですか。丈夫なわけですね。[Are you swimming in the pool every day? No wonder you’re strong.]
昨日は三時間しか寝ていない。道理で眠いわけだ。[Yesterday I only slept for 3 hours. No wonder I’m so sleepy.]
WILD Examples:


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