가: 도쿄 여행은 어땠어요? 재미 있었어요?
How was your trip to Tokyo? Was it interesting?
나: 네, 그렇지만 도쿄의 물가가 얼마나 비싼지 몰라요. 물가가 비싸니까 쇼핑을 마음대로 못 해서 아쉬워요.
Yes, but I can’t tell you how expensive things were there. The prices were so high that unfortunately, I couldn’t shop like I had wanted to.
가: 왜 그렇게 놀란 표정이에요?
Why do you look so surprised?
나: 책을 읽고 있는데 갑자기 문이 열려서 얼마나 놀랐는지 몰라요.
I was reading a book, and the door opened suddenly and really surprised me.
This expression is used to emphasize the degree of a particular situation or state of affairs, it can only be used m declarative sentences and can be used with both verbs and adjectives.
• 호영 씨가 어렸을 때 친구들에게 얼마나 인기가 많았는지 몰라요.
Hoyeong was very popular among his friends when he was growing up.
• 우리 아이가 7살이 되더니 얼마나 말을 안 듣는지 모릅니다.
I can’t describe how disobedient our son became as soon as he turned seven.
• 잃어버린 강아지를 조금 전에 찾았어요. 강아지를 다시 찾아서 얼마나 기쁜지 몰라요.
I found my lost puppy a little while ago, I’m so happy to have found my puppy again.
1. When used with a verb, this expression must be used together with a degree adverb such as 열심히, 잘, 많이, or 못.
• 자야 씨가 얼마나 공부하는지 몰라요.(X)
->자야 씨가 얼마나 열심히 공부하는지 몰라요. (〇)
Here, without the adverb 열심히, the sentence means that the speaker does not know the amount of time that Jay a studied. Thus a degree adverb is necessary.
• 아키라 씨는 얼마나 많이 먹는지 몰라요. (〇)
2. However, it is unnecessary to use a degree adverb when expressing the speaker’s feelings or attitude toward something, such as with the expressions 짜증이 나다, 화가 나다 and 감동하다.
• 길이 막혀서 얼마나 짜증이 나는지 몰라요.
You can’t imagine how upset I was because of the traffic jam.
• 그 영화를 보고 얼마나 감동했는지 몰라요.
I can’t tell you how much I was touched after seeing that movie.
3. When used to refer to past situations or states of affairs, the form ‘-았/었는지 물라요’ is used.
• 어제는 바람이 많이 불어서 얼마나 추웠는지 몰랐어요. (X)
->어제는 바람이 많이 불어서 얼마나 추웠는지 몰라요. (〇)
>> You can click on the title of each grammar below to learn about the other grammar which also expresses ‘Emphasis’:
01 얼마나 -(으)ㄴ/는지 모르다
02 -(으)ㄹ 수밖에 없다
03 -(으)ㄹ 뿐이다
04 (이)야말로
>> Full of Intermediate grammar: Click here