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as expected; just as one thought; as feared; sure enough
案の定、彼は遅刻してきたので驚かなかった。
As expected, he arrived late.
案の定うまくいかなかったと報告を受けました。
Sure enough, it started to rain.
案の定、彼は約束の時間に三十分も遅れて現れた。
As expected, he showed up thirty minutes late for the appointment.