The way i think of it is like this: Normal 해요 is like english "does" and it suggests 'presently' a bit more generally. For example: 수연이 먹어요 = Soo-yeon eats. Progressive present tense 하고 있어요 is like "ing" in english and (in the way i think of the difference) suggests what is being done now/ in the process of doing, and is less general. For example 수연이 먹고 있어요 = Soo-yeon is eating However I have found that in korean, people often seem to use them interchangably, so i wouldnt worry too much :) Basically the difference is the same as english "does" (present tense) vs "is doing" (progressive present tense)

present tense -아/어/여요 present progressive tense -하고 있어요 e.g. In present tense:- 가 : 뭐해요? 나 : 공부(를) 해요. In present progressive tense:- 가 : 뭐하고 있어요? 나 : 공부하고 있어요 koreans use present tense most of the times to even specify present progressive tense

Present ~하다 vs Present progressive ~하는 중이다 or ~ 중이다 나는 공부한다 I study 나는 공부하는 중이야 or 나는 공부 중이야 I'm studying 그녀는 밥을 먹는다 She eat a dinner 그녀는 밥을 먹는 중이다 She is eating a dinner