This post was inspired by a question that someone asked on the /r/korean subreddit (I lurk around there sometimes; if you Reddit, please do check out that sub!). The question was why some verbs use -고 있다 and some use -아/어 있다. If you check the question link, you can see my short answer on the original question. Also, I’ve actually gone over these two in the past, in a post about the progressive tense. The purpose of this post is to sort of clarify the difference between the two with a bit more explanation and contrasting examples.
In English, we use the progressive tense very commonly, and it’s just as useful in Korean. The progressive tense is used any time you want to indicate that an action or state is ongoing. For example:
I’m going to the store.
He is eating an apple.
Of course, it can be used in more than just the present tense. We also have past progressive:
I was doing my homework.
He was reading a book.
And we have future progressive as well:
I will be cooking dinner.
They will be taking a test.
So how do we make these kinds of sentences in Korean? There are a few simple ways.