noun + 때 (방학 때) · verb + -(으)ㄹ 때 (어릴 때)
time, moment; when
Example
저는 어릴 때 부산에 살았어요.
I lived in Busan when I was young.
Word parts
어릴 때 = when I was young. Heads-up: 때 also means dirt or grime.
Good to know
-(으)ㄹ 때 means 'when ~': 시간이 있을 때 = when I have time.