Before
(can also be used for ‘ago’)
N + 전에
V + 기 전에
Afterwards
N + 후에
V + 은 후에
Afterwards (as in this happens and then that happened).
고 나서
So / Therefore
V (Present Tense) + 서
During / When
N 때
V 을/를 때
While (doing something)
V (으) 면서
In the middle of doing something
N 중
V 는 중
As soon as, Right after
V 자마자
During, While (i.e involving two people), For
N 동안
V 는 동안
Since/ For some Duration
V ㄴ지 … 되었어요
V 은 지 … 되었어요
(also 넘었어요 for less precise duration e.g. over 30 years)