Tense

Question 1

-았었-
-었었-

Answer 1

indicates that something happened in the past, usually a long time period ago than 았/었

Question 2

-았/었

Answer 2

past tense connector

Example:
밥 먹었어요.

Example:
영화 봤어요.

Question 3

-겠

Answer 3

assumed future based on current circumstance connector