접속사  because, since, as, now that

We didn’t stay outside long because it was too cold.
너무나 추웠기 때문에 우리는 밖에 오래 머물지 못했다.

Since it is very likely that local people are in greater danger from these crimes, plans to prevent them must be made immediately, he said.
(출처: The Korea Herald)
“외국인 범죄로 내국인들이 더 큰 위험에 봉착할 가능성이 매우 높기 때문에 이를 예방하기 위한 방안이 시급히 마련되어야 한다”고 그는 말했다.

As I was tired, I soon fell asleep.
피곤했기 때문에 곧 잠들었다.

now that the weather is warmer
날씨가 꽤 따스해졌으니까

vs.

전치사 because of, due to, owing to, thanks to, on account of, by reason of

go out of business because of outdated technology (출처: 동아 프라임 영한사전)
기술 낙후로 폐업하다

Among the 31 crashes, 21 were due to pilot error and the rest were due to mechanical defects. (출처: The Korea Herald)
추락사고 31건 중 21건은 조종사 실수로 인한 것이었고 나머지는 기계장치의 결함 때문이었다.

The accident was owing to careless driving. (출처: 동아 프라임 영한사전)
사고의 원인은 부주의한 운전이었다.

Thanks to the brisk performance, the market capitalization of the Korea Exchange has jumped 60.35 percent to $490.98 billion. (출처: The Korea Herald)
활발한 상승세로 인해 국내 증시의 시가총액은 60.35% 크게 증가한 4,909억8천만달러를 기록했다.

The airport was closed on account of the fog. (출처: BBI Word Combi)
공항은 안개 때문에 폐쇄되었다.

He was excused by reason of his age. (출처: OALD)