1) 있어요 can be used as a simple present tense of 'be verb.' 나는 집에 있어요. ☞ I'm at home. 그는 서울에 있어요. ☞ He is in Seoul. 2) ~(하)고 있어요 can be used as a present progressive form. 나는 집에 가고 있어요. ☞ I'm going home. 그는 서울에 살고 있어요. ☞ I'm living in Seoul. 3) ~(하)고 있었어요 can be used a past progressive form. 나는 TV를 보고 있었어요. ☞ I was watching TV. 그는 밥을 먹고 있었어요. ☞ He was eating a meal. * -어요 is an inflection for verbs. -어요 is the basic verb form of spoken Korean. 하다(do) ☞ 했어요 있다(be) ☞ 있어요 만들다(make) ☞ 만들어요 * -아요, -애요 aren't grammtically correct.

When 있다 is used only, it means 'being in somewhere.' But when using with other verbs, it plays auxilary verb role to represent tense. So '있어요' means that staying right now for example "나 집에 있어요=I'm home." But when using other verbs such as '고 있어요', '고 있었어요' are presenting different tenses. For instance, "나 밥먹고 있어요" is present progressive like "I'm eating." And "나 밥먹고 있었어요" is past progressive such as "When I got there, he was eating". 어요,아요 and 애요 are all used for present tense, so these aren't replaced with "고 있어요 and

verb+고 있다 is present progressive. and also, express repeat, a habit. e.g 매일 운동을 하고 있어요.(habit) I'm doing a excise every day. 자주 영화를 보고 있습니다. (repeat) I'm watching movie very often. Tense 지금 그림을 그리고 있습니다.(in present) now, I'm drawing a picture. 어제 그림을 그리고 있었습니다.(in past) yesterday, I was drawing a picture. 내일 그림을 그리고 있겠습니다.(in future) tomorrow, I will draw a picture.