많았고

In a sentence

• 작년에 눈이 정말 많았고 겨울이 길었어요.

  Last year, there was a lot of snow and the winter was long.

  Here, '많았고' refers to the substantial amount of snow ('많다' in past tense and connected to the following clause with '고').

• 그곳에는 관광객들이 정말 많았고 모두가 즐거운 시간을 보냈습니다.

  There were many tourists there, and everyone had a good time.

  The usage of '많았고' here highlights the significant number of tourists, combining it with '고' to provide additional context.

• 행사장에 사람들이 많았고 분위기도 매우 좋았어요.

  There were many people at the event venue, and the atmosphere was very good.

  In this sentence, '많았고' is used to describe the high number of people present at the event, serving as a foundation for the subsequent observation.