Key Facts
- ㄴ is added in compounds and derivations: 한여름 is [한녀름].
- The trigger is a second part starting with 이, 야, 여, 요 or 유 after a consonant.
- After ㄹ the inserted ㄴ becomes ㄹ: 서울역 is [서울력].
- Nasalization often follows the insertion: 색연필 is [생년필].
- The extra sound is not in the spelling and must be learned by ear.
- Rule reference: Article 29 of the Standard Pronunciation Rules (표준 발음법); Article 30 covers words written with 사이시옷.
Last updated: 2026-10-09. The Korean text, romanization and audio scripts in this section were generated and reviewed and signed off by Min-ji Park on 15 October 2026.
What Is Korean N Insertion?
Korean n insertion is a sound change that adds a consonant that the spelling does not show. It happens inside compound words and words with a prefix or suffix, which are words built from smaller parts. When the first part ends in a consonant and the second part starts with 이, 야, 여, 요 or 유, a ㄴ is spoken between them.
Take 한여름, "midsummer", which is 한- (the height of) plus 여름 (summer). The first part ends in ㄴ and the second starts with 여, so the speaker adds a ㄴ and says [한녀름]. The extra sound must be heard, because it is not on the page.
| Written | Spoken | Revised Romanization | What happens | Meaning |
|---|---|---|---|---|
| 한여름 | [한녀름] | hannyeoreum | ㄴ inserted | midsummer |
| 색연필 | [생년필] | saengnyeonpil | ㄴ inserted, then nasalization | coloured pencil |
| 담요 | [담뇨] | damnyo | ㄴ inserted | blanket |
| 서울역 | [서울력] | Seoullyeok | inserted ㄴ becomes ㄹ after ㄹ | Seoul Station |
Revised Romanization (RR) writes these sounds as spoken, so 한여름 is hannyeoreum. RR is a learning aid on this site, and the Hangul and the bracketed forms are the reference. The table below sends each learner to the right lesson.
Where to Start with Korean ㄴ Insertion
Start with the lesson that matches the word you want to say. The table gives one starting point for each situation.
| If you want to say... | Start with |
|---|---|
| 한여름, 색연필, 담요, 맨입 or 식용유 | Korean N Insertion Rules |
| 서울역, 알약, 물약, 불여우 or 휘발유 | Korean N Insertion with ㄹ |
| 금요일, 목요일, 6·25 or 검열 | Korean N Insertion Exceptions |
A beginner should take the three lessons in this order, because the ㄹ case and the exceptions are both defined against the main rule. The main rule comes first.
What Is the N-Insertion Rule?
The n-insertion rule says that ㄴ is added when a consonant-final first part meets a second part that starts with 이, 야, 여, 요 or 유. The lesson Korean N Insertion Rules teaches it with 한여름, 색연필, 담요, 맨입 [맨닙] and 식용유 [시굥뉴].
The lesson stresses that the extra sound is not in the spelling, so it has to be heard and learned word by word. It also shows the second step in 색연필. After the ㄴ is added, the final ㄱ of 색 sits before a nasal and becomes ㅇ, which gives [생년필]. That step is the nasalization rule at work. The ㄹ case is next.
What Happens after ㄹ?
After ㄹ, the inserted ㄴ is pronounced ㄹ. The lesson Korean N Insertion with ㄹ teaches 서울역 [서울력], 알약 [알략], 물약 [물략], 불여우 [불려우] and 휘발유 [휘발류].
The reason is the same one that drives Korean liquidization: ㄴ next to ㄹ is not stable in standard speech, so the added ㄴ becomes ㄹ. Learners who know the liquidization rule can predict these words. A few words do not follow the pattern, and they have their own lesson.
Which Words Are Exceptions?
The exceptions are words where the extra ㄴ is not added, or where both forms are accepted. The lesson Korean N Insertion Exceptions covers 금요일, 목요일, 6·25 [유기오] and 검열, and it names which ones are optional.
The Standard Pronunciation Rules list a few words with no inserted ㄴ, such as 6·25 [유기오], and a few with two accepted forms, such as 검열. The lesson sorts them so that you know which pronunciation to use when speaking and which to expect when listening. The table below compares the three lessons.
Comparing the Korean ㄴ Insertion Lessons
The table compares the lessons by what each one fixes, its level and its length.
| Lesson | What it fixes | Level | Time | Audio |
|---|---|---|---|---|
| Korean N Insertion Rules | the main rule and its triggers | B1 | about 30 minutes | 7 clips |
| Korean N Insertion with ㄹ | the ㄹ result | B1 | about 25 minutes | 7 clips |
| Korean N Insertion Exceptions | words with no or optional ㄴ | B1 | about 25 minutes | with audio |
Every lesson uses real vocabulary such as 한여름, 담요 and 서울역 as headline examples. The next question is how to practise between lessons.
How Do You Practise Korean ㄴ Insertion?
Practise by spotting the join between two parts of a word and checking the first letter of the second part. Use this routine.
- Split 한여름 into 한 and 여름, and notice the 여 at the start of the second part.
- Say the added sound before the vowel: [한녀름].
- Do the same for 담요 [담뇨] and 맨입 [맨닙].
- After ㄹ, switch the added sound to ㄹ: 알약 [알략] and 서울역 [서울력].
The rule also works across a space when two words are said together, as in 한 일 [한닐], but a careful reader of written text does not need it for every phrase. A related change at the join of compounds is sai-siot. For the overview of all rules, see Korean pronunciation rules.
Study Order at a Glance
Take the main rule first, the ㄹ case second and the exceptions third. The main rule is the base. The ㄹ lesson applies one extra step, and the exceptions lesson comes last because it asks you to hold the rule and its counter-examples together.
What Does This Section Cover, and What Does It Leave Out?
The section covers n insertion in standard Seoul-based pronunciation, as set out in Article 29 of the Standard Pronunciation Rules (표준 발음법). Article 30 is the separate rule for words written with 사이시옷. It does not predict every compound, because some words are variable and a dictionary is the final check. The audio is machine-generated and was approved by Min-ji Park on 15 October 2026.
Frequently Asked Questions
What is n-insertion in Korean? N-insertion (ㄴ 첨가) is the sound change in which an extra ㄴ is spoken between two parts of a compound word when the first part ends in a consonant and the second starts with 이, 야, 여, 요 or 유. The ㄴ is not written, so 한여름 is said [한녀름].
Why is 한여름 pronounced 한녀름? The word joins 한 and 여름. The second part starts with 여 and the first part ends in a consonant, so Korean adds a ㄴ between them. The result is 한 + 녀름, written 한여름 but said [한녀름]. The same logic gives 담요 [담뇨] and 맨입 [맨닙].
Does n-insertion apply across spaces? Sometimes. The Standard Pronunciation Rules allow it when two words are said together in one phrase, as in 한 일 [한닐] and 옷 입다 [온닙따]. In careful reading of separate words it is not required. Within a single compound word it is the normal pronunciation.
Which words are exceptions to n-insertion? A few words are said without the extra ㄴ, such as 6·25 [유기오], and a few accept two forms, such as 검열. The lesson on exceptions sorts them. Because variable words exist, check an unfamiliar compound in a dictionary instead of assuming the rule applies.
Where to Go Next
To see all sound changes together, return to Korean pronunciation rules. To continue, open Korean N Insertion Rules, the first of the lessons on Korean n insertion.