Progressive aspect: 고 있다 (be doing)

Think of 고 있다 like a Lego brick that you snap onto the end of a verb. It is incredibly reliable because it does not care about the final consonant of the verb stem. Whether your verb ends in a vowel or a consonant, the rule stays the same. You just take the base form of the verb, chop off the 다 at the end, and glue on 고 있다. That is it. No complex spelling changes or weird exceptions to memorize here. It is one of the friendliest grammar rules in the Korean language. Even if the verb stem ends in a tricky ㄹ or ㅂ, you do not have to worry about those changing. You just attach 고 and you are good to go. It is like the grammar version of an easy-access ramp.

1. 1Creating this pattern is as simple as making instant ramen. Here is your three-step recipe:
2. 2Find the dictionary form of the verb (e.g., 가다 - to go).
3. 3Remove the 다 to get the verb stem (가).
4. 4Add 고 있다 to the stem (가고 있다).
5. 5Let’s look at a few examples to see this in action:
6. 6먹다 (to eat) → 먹 + 고 있다 → 먹고 있다 (am eating)
7. 7공부하다 (to study) → 공부하 + 고 있다 → 공부하고 있다 (am studying)
8. 8씻다 (to wash) → 씻 + 고 있다 → 씻고 있다 (am washing)
9. 9If you want to be polite (which you usually do!), you change the 있다 part to 있어요 or 있습니다. If you are talking to a boss or someone much older, you should use the honorific version: 고 계시다. For example, 선생님이 주무시고 계세요 (The teacher is sleeping).

Use 고 있다 whenever you want to emphasize that an action is currently in progress. Imagine you are at a cafe and your mom calls you. She asks, "What are you doing?" You respond with 커피를 마시고 있어요 (I am drinking coffee). This tells her that right at this moment, the cup is in your hand and you are taking sips. You can also use it for longer-term actions that are "ongoing" in your life. For instance, if you are taking a Korean class this semester, you can say 한국어를 배우고 있어요. Even if you are not holding a textbook at this exact second, the process of learning is still happening in your life. It is also great for describing what people are wearing. Interestingly, in Korean, once you put something on, you "are wearing" it using this form, like 코트를 입고 있어요 (I am wearing a coat).

Here is where it gets a bit tricky. You cannot use 고 있다 with adjectives. In Korean, adjectives are like "descriptive verbs," and they describe a state, not an action. You cannot be "ing-ly" pretty or "ing-ly" cold. So, avoid saying things like 날씨가 춥고 있어요. Instead, just say 날씨가 추워요 (The weather is cold). Also, avoid using it with verbs that represent a natural state or a fixed fact. For example, if you want to say you "know" something, you usually just say 알아요 or use the special form 알고 있어요, but for most states, the plain present tense is better. Think of it like a grammar traffic light: green for actions, red for adjectives.

One big mistake is trying to use 고 있다 to describe the result of an action. For example, if you sit down and you are now in a seated position, you do not say 앉고 있어요 unless you are literally in the process of lowering your butt into the chair. If you are already sitting, you use a different grammar point (앉아 있다). Another classic mix-up is forgetting to conjugate the 있다 part. Remember, 고 있다 is just the base. You still need to add your 어/아요 or ㅂ니다 endings to the end of it. Yes, even native speakers mess this up sometimes when they are in a rush, but as a learner, keeping your endings straight will make you sound much more polished. Don't let your verb stems get lonely—always give them an ending!

You might have seen 는 중이다 and wondered if it is the same thing. They are close cousins! 는 중이다 also means "in the middle of doing something," but it feels a bit more formal or focused on the task. If 고 있다 is a casual "I'm eating," then 는 중이다 is more like "I am currently in the process of eating." Use 고 있다 for most daily situations. Also, compare it to the plain present tense. 공부해요 can mean "I study" (generally) or "I am studying" (now). However, 공부하고 있어요 is much more specific. It screams "Do not disturb me, I am actually in the middle of this right now!" It adds that extra layer of focus that the plain present tense lacks.