訳だ
For that reason, No wonder, As you'd expect, Naturally, Thus, This is why
Structure
［い］Adjective + (という) + わけだ
［な］Adjective + な(1) + わけだ
Noun + の(1) + わけだ
(1) という
Explanation
The word 訳 is often a source of confusion for learners of Japanese. While it can be translated in various ways, such as 'reason', 'meaning', or 'cause', it's often more helpful to think of it as a way to express a logical conclusion or natural outcome based on a given situation.
At its core, わけ points to the logical result or explanation for something. This function is clearly seen in its most common grammatical form, わけだ, which is a combination of わけ and the auxiliary verb だ.
Typically found at the close of a sentence, わけだ may also follow the particle という. This pattern is frequently used to mean 'it makes sense that (A)', 'so that's the reason (A)', or 'no wonder (A)'. In essence, it conveys the idea of 'so, it is naturally the case that (A)'.
- 大雪でバスが来ないの？だからみんな駅で待っているというわけだ。The bus isn't coming because of the heavy snow? So that's why everyone is waiting at the station.
- ケーキを三つも食べたのですね。だからお腹が痛くなったという訳ですね。You ate three pieces of cake? So that explains why your stomach started to hurt.
- やっぱり全然勉強してないでしょ？どうりでテストに落ちたわけだ。Just as I thought, you didn't study at all, did you? No wonder you failed the test.
- もう夜の十時か。だからお店が閉まっているわけだ。It's already 10 PM? So that's why the store is closed.
Because わけ functions as a noun, any preceding word must be in its attributive form (the form used to modify nouns). As demonstrated, the nuance of わけ is closely tied to logical consequence, covering a range of meanings from 'that's the reason' to expressions of understanding like 'it makes sense' or 'as one would expect'.
わけ can also appear in questions when the speaker is trying to confirm an inference they've made based on what they've seen or heard. Common examples of this include わけだね, meaning 'so it's (A), right?', and わけですか, meaning 'so, does that mean (A)?'.
- 明日は来られないの？つまり、忙しいわけだね？分かったよ。You can't come tomorrow? So that means you're busy, right? I get it.
- 会議が中止になったんですね。では、会社に行かなくてもいいというわけですか？The meeting was canceled. So, does that mean we don't have to go to the office?
Examples
昨日の夜、全然寝てないんだ。眠い訳だ。
I didn't sleep at all last night. No wonder I'm so sleepy.
彼は毎日運動している。健康な訳だ。
He exercises every day. No wonder he is healthy.
フランスに１０年も住んでいたんだ。フランス語がペラペラな訳だ。
He lived in France for 10 years. No wonder he's fluent in French.
あ、傘をさしている人がいる。外は雨が降っている訳だ。
Oh, there's someone using an umbrella. That must mean it's raining outside.
値段は安いですが、すぐ壊れます。だから人気がない訳です。
It's cheap, but it breaks easily. That's why it isn't popular.
全然勉強しなかったんだ。だからテストに落ちた訳だ。
He didn't study at all. That explains why he failed the test.
彼の趣味はパソコンだそうだ。どうりでコンピューターに詳しい訳だ。
I hear his hobby is computers. No wonder he knows so much about them.
上着を忘れてきたのか。それで震えている訳だ。
You forgot your jacket? Ah, that's why you're shivering.
田中さんが掃除してくれたんだ。こんなにきれいな訳だ。
Tanaka-san just cleaned. No wonder it's so clean.
赤ちゃんがおなかを空かせている。それで泣いていたという訳だ。
The baby is hungry. So that explains why it was crying.
充電が切れていたんだ。電話がつながらない訳だ。
The battery was dead. No wonder the call wouldn't connect.
彼は毎日トレーニングしている。優勝する訳だ。
He trains every single day. It's only natural that he would win the championship.