-았/었/였으면 좋겠다 is the grammatical structure that expresses a wish or a hope, and just like when the English verb 'to wish' is used, the conjugated structure of the verb in Korean is also usually in the past tense. The form in the present tense, -(으)면 좋겠다 can also be used, but the past tense is more commonly used, especially with the ending part “좋겠다”. 그가 왔으면 좋겠어요 = I wish he would come. it would be good if he would come. 그가 했으면 좋겠어요 = I wish he would do it. it would be good if he would do it. 하와이의 해변에서 가족 사진을 찍을 수 있었으면 좋겠습니다. It would be good if I would take a family picture at the Hawaiian beach .