主題:自從他父母過世後, 他就一直住在LA或不是

現在完成式: Ever since his parents passed away, he has been living in LA. 意思: Timeline: -----------x1---------------------------------------x2 x1 = 他父母過世 x1~x2 = 住在LA x2 = 現在 過去完成式: Ever since his parents passed away, he had been living in LA until he met Carol last year. 意思: 自從他父母過世後, 他就一直住在LA, 直到一年前他認識Carol. Timeline: -----------x1---------------------------------------x2----------------x3 x1 = 他父母過世 x1~x2 = 住在LA x2 = 一年前他認識Carol x3 = 現在 x2~x3 = 認識Carol後, 到現在不再住在LA了