Yg kamu maksud expressing regret?

A: Hi John..where were you last night? why didn’t you come to my birthday party? (simple past tense)
B: I’m so sorry, I wish I could come to your birthday party, but my father had come (past perfect) to visit me before I went. So I couldn’t go. did Jack come?
A: yeah, but I he went home when we were singing together (past continous) because his mother was sick.
B: I am so sorry to hear that. was the party cool?
A: yes, we had been singing together for 3 hours on my backyard’s home when finally rain came fall down.
B: well, next year I must come to your birthday party bro.
A: Ok, I will be glad.