Learn Korean: Verb + 는지

Let’s take a look at the Korean sentence pattern Verb + 는지. We use this to express what we know, but the object must be a noun clause that begins with a question word. Here are some examples: I know / why he did it, I know / where he lives, and I know / what he likes. The second part is the noun clause and it is expressed through 는지. If we convert them into questions, they become Why did he do it? Where does he live? and What does he like? In Korean, they are 왜 했어(요)? 어디에 살아(요)? and 뭘 좋아해요? It is essential that we know how to make questions in Korean. The main verb of the questions are 했다, 살다, and 좋아하다. We get rid of 다 and replace it with 는지. They become 왜 했는지 (why he did it), 어다에 사는지 (where he lives), and 뭘 좋아하는지 (what he likes). In the case of 살다,  ㄴ disappears when followed by ㄹ. So we say 사는지 instead of 살는지. To complete the sentence, we need the verb 알다 to say that we know. It is the main verb of the examples above. The actual sentences are 왜 했는지 알아(요), 어디에 사는지 알아(요), 뭘 좋아하는지 알아(요).

걔가 그걸 왜 했는지 알아.
I know why he did it.

걔가 어디에 사는지 알아.
I know where he lives.

걔가 어떤 거 좋아하는지 알아.
I know what he likes (among the choices).