～て当然だ
Natural, As a matter of course
Structure
［い］Adjective［て］+ 当然 + だ
［な］Adjective + で + 当然 + だ
Explanation
The phrase て当然だ is used to express that something is 'only natural' or 'to be expected'. It is formed by taking the て-form of a verb or い-adjective (or で for a noun or な-adjective), followed by the noun 当然 which means 'natural' or 'a matter of course', and the copula だ.
- 彼は毎日勉強したから、試験に合格して当然だ。He studied every day, so it is only natural that he passed the exam.
- この問題は小学生のレベルだから、易しくて当然だ。This problem is at an elementary school level, so of course it's easy.
- 彼女はプロのモデルだから、おしゃれで当然だ。She's a professional model, so of course she's fashionable.
Because て当然だ carries a strong sense of conviction, it is often used when stating something the speaker believes is an undeniable or logical outcome.
Examples
毎日一生懸命勉強したのだから、試験に受かって当然だ。
Since you studied so hard every day, it's only natural that you passed the exam.
彼はいつも嘘をつくから、だれからも信用されなくて当然だ。
He's always lying, so it's no wonder that nobody trusts him.
あのレストランは値段が高いのだから、おいしくて当然だ。
Considering how expensive that restaurant is, it's expected to be delicious.
何年もトレーニングしてきたのだから、彼が上手で当然だ。
He's been training for years, so of course he's good at it.
全然勉強しなかったのだから、テストに落ちて当然だ。
You didn't study at all, so of course you failed the test.
彼は毎日きちんと練習しているから、勝って当然だ。
He practices properly every day, so it's no surprise that he won.
毎日残業しているのですから、疲れていて当然です。
You're working overtime every day, so of course you are tired.
一日中歩き回ったのだから、足が痛くて当然だ。
You've been walking around all day, so it's natural for your legs to hurt.
彼は仕事に不真面目だから、解雇されて当然だ。
He's not serious about his job, so it's only right that he got fired.
大きな大会で優勝したのだから、喜んで当然だ。
You won a major competition, so it's only natural to be happy.
真冬なのだから、寒くて当然です。
It's the middle of winter, so of course it's cold.
あれは傑作なのだから、褒められて当然だ。
That's a masterpiece, so it's no wonder it's praised.