Oftentimes you will have to say you are in the middle of doing something and there are a few ways to do that in Korean. One of the ways how you can say some action or event is under way is by using the Korean time expression 중.
중 is one of the Korean grammar topics that is based around Hanja, like 후에 and 전에. The character, on which it is based is, 中 [중], which means ‘middle’. It clearly gives away the purpose of this specific grammar topic. The purpose of 중 is to indicate an event, state or action is in the middle of happening. In this regard it is nearly identical to the Korean progressive tense, -고 있다. However, there is a slight difference between the two.
가: 왜 여기에는 너무 시끄러워요?
나: 우리 집 옆에서 섬성 사옥 공사 중이에요.
A: Why is it too noisy here?
B: They are building a Samsung office next to our house.
How To Use
Using the Korean time expression 중 is pretty simple once you understand it is technically nothing more than a noun itself. Therefore, when you use it with another noun, you simply put the noun before it and you are done. With verbs, you simply need to turn it into a present tense noun phrase. To do that you simply need to attach -는 to the verb stem and you are done. Just keep Korean irregular verbs in mind like the ㄹ irregular verbs. Remember that you can either use the noun or a noun phrase when the verb is a 하다 verb.