had already left
彼が駅へ着いたら汽車は出た後だった。
By the time he arrived at the station, the train had already left.
私が着いたとき彼女はもう出た後だった。
She had already left by the time I arrived.
トムが駅に着いたとき、電車はもう出た後だった。
When Tom arrived at the station, the train had already left.
私が駅に到着した時には、電車は既に出た後だった。
By the time I arrived at the station, the train had already left.