When to use lecture in Korean
Korean: 강의[ gang-ui ]

When to use it
A lecture (강의) is a class or talk where a teacher or expert explains something to students. You often use this word at school, university, or for online classes. You can say you listen to a lecture, take a lecture, or talk about whether a lecture is easy or hard.
Example sentences
오늘 강의는 세 시에 시작해요.
Today's lecture starts at three.
저는 집에서 온라인 강의를 들어요.
I take an online lecture at home.
이 강의는 정말 재미있어요.
This lecture is really interesting.
친구와 같이 한국어 강의를 들어요.
I take a Korean lecture with my friend.
교수님 강의가 조금 어려워요.
The professor's lecture is a little difficult.
기차에서도 휴대폰으로 강의를 들어요.
I listen to a lecture on my phone even on the train.