[Grammar] -고 있다 : action in progress, -ing

verb+고 있다  ~ing

-고 있다 means an action in progress like in English ‘-ing’.

Present tense ; – 고 있어요.
Past tense : -고 있었어요.
Future tense : -고 있을 거예요.

For example,
지금 뭐 하고 있어요? What are you doing now?
밥 먹고 있었어요.  I was eating a meal.
책 읽고 있어요.  I am reading a book.
텔레비전 보고 있어요.  I am watching TV.
숙제하고 있었어요.  I was doing my homework.
백화점 앞에서 친구를 기다리고 있었어요.  I was waiting for my friend in front of the department store.
휴대 전화를 보고 있었어요. I was looking at my phone.
10년 후에 한국에서 살고 있을 거예요.  I will be living in Korean 10 years from now.

You can listen to the audio here(click).