Korean N Insertion with ㄹ: Sounds, Rules and Examples

What you will learn

• Say 서울역, 알약, 물약, 불여우 and 휘발유 with the [ㄹㄹ] result.
• Explain the two-step chain: n-insertion first, then lateralization.
• Tell n-insertion words from liaison words ending in ㄹ, such as 월요일 and 서울에.
• Apply the change across a space in phrases like 할 일.

Before you start: you know the four-step test from Korean N Insertion Rules and that ㄹ + ㄴ sounds [ㄹㄹ] from Korean liquidization. Time: about 25 minutes with audio.

Key Facts

• When the first part ends in ㄹ and the second part starts with 이, 야, 여, 요 or 유, the inserted ㄴ becomes ㄹ: 서울역 is [서울력].
• Two rules apply in order: n-insertion adds ㄴ, then lateralization turns ㄴ after ㄹ into ㄹ.
• Common examples: 알약 [알략], 물약 [물략], 휘발유 [휘발류], 불여우 [불려우], 솔잎 [솔립].
• Particles and one-piece words get liaison instead: 서울에 is [서우레] and 월요일 is [워료일].
• The change can cross a space in one breath: 할 일 is [할릴] and 스물여섯 is [스물려섣].
• The rule is a note (붙임 1) to Article 29 of the Standard Pronunciation Rules (표준 발음법).

Last updated: 2026-10-09. The Korean text, romanization and audio scripts on this page are generated drafts that still await review by a Korean specialist.

What Is Korean N Insertion with ㄹ?

Korean n insertion with ㄹ is a two-rule chain inside compounds whose first part ends in ㄹ. A compound is a word built from two parts that each have their own meaning, such as 서울 (Seoul) and 역 (station). The second part must start with 이, 야, 여, 요 or 유, the same five trigger vowels as in ordinary n-insertion.

The only new element is what happens to the inserted sound. After a final ㄴ, ㅁ or ㅇ, the inserted ㄴ stays ㄴ: 한여름 is [한녀름]. After a final ㄹ, the inserted ㄴ cannot survive, and it becomes ㄹ.

Revised Romanization (RR) writes the result, so 알약 is allyak. The romanization rules use 알약 itself as an example of an added sound. RR is a learning aid here; the Hangul and the bracketed forms are the reference. Learners usually have one specific problem with these words.

Why 서울역 Is Not "Seo-U-Ryeok"

Learners read 서울역 as "seo-u-ryeok" because they apply liaison, the rule that moves a final consonant into a following vowel. Liaison would move the ㄹ of 서울 into 역, giving *[서우력], with a single flapped ㄹ. Koreans say [서울력], with the l held across the syllable break.

The difference is easy to hear once you know it. In *[서우력] the second syllable is "u", and the ㄹ is a quick tap. In [서울력] the second syllable is "ul", and the tongue stays on the ridge behind the teeth into "lyeok".

A wrong form here is noticeable, because 서울역 is a name every visitor hears in station announcements and asks for in taxis. The next section sets out exactly what happens after ㄹ.

What Happens after ㄹ?

After ㄹ, the inserted ㄴ becomes ㄹ, so the five trigger syllables become [리], [랴], [려], [료] and [류]. The ㄹ of the first part stays as a final, and the new ㄹ starts the next syllable. Article 29 of the Standard Pronunciation Rules (표준 발음법), published by the National Institute of Korean Language (국립국어원), adds this case as a note (붙임 1) to the main n-insertion rule.

The vowel 요 follows the same pattern and would give [료], but common ㄹ + 요 compounds are rare at this level, so the table leaves it out. The result is always a double [ㄹㄹ], pronounced as a held l. The reason two rules are needed, rather than one, is the subject of the next section.

Why Two Rules?

Two rules are needed because each one does a different job. N-insertion supplies a consonant where there was none, and lateralization fixes the illegal sequence ㄹ + ㄴ that n-insertion creates. Article 20 of the Standard Pronunciation Rules states that ㄴ after ㄹ is pronounced ㄹ, as in 설날 [설랄].

Follow the order in 알약:

1. Start with the spelling: 알 + 약.
2. Apply n-insertion: 약 starts with 야 and is a meaning word, so ㄴ is added: 알 + [냑].
3. Apply lateralization: ㄹ + ㄴ is not allowed, so ㄴ becomes ㄹ: 알 + [략].
4. Result: [알략].

The order matters. If lateralization came first, there would be no ㄴ for it to change, and the result would be plain liaison, *[아략]. Linguists call this a feeding order: the first rule creates the input for the second. With the mechanism clear, a larger word list shows how widely it applies.

Which Words Show It?

The pattern appears in everyday compounds for medicine, food, nature and transport. Every word below has a first part ending in ㄹ and a meaning-bearing second part starting with a trigger vowel.

In 물엿 the final ㅅ of 엿 is pronounced [ㄷ] at the end of the word, so the full form is [물렫]. In 설익다 a third rule, tensification, makes the ㄷ of 다 tense: [설릭따]. The words that learners say most often, though, are station names.

Station Names and Travel Words

Station names are where most learners meet this rule, because 역 (station) starts with 여. Any station whose name ends in ㄹ gets [력], and any station whose name ends in another consonant gets [녁].

Expert tip: when you ask for a station, say the name and 역 as one word, with no pause. A pause before 역 sounds unnatural, and it also removes the cue that the listener expects. Station names come up constantly in directions phrases, such as 서울역이 어디예요? (Where is Seoul Station?), spoken [서울려기 어디예요]. The same chain can also cross a space.

Across a Space: 할 일 and 스물여섯

The ㄹ case of n-insertion also crosses a word space when two words are said in one breath. Article 29 lists 할 일 (things to do) as [할릴], 잘 입다 (to dress well) as [잘립따] and 스물여섯 (twenty-six) as [스물려섣].

• 할 일 → [할릴]: the verb form 할 ends in ㄹ, and 일 (work, task) starts with 이.
• 스물여섯 → [스물려섣]: 스물 (twenty) ends in ㄹ, and 여섯 (six) starts with 여.
• 1 연대 (the 1st regiment) → [일련대]: 일 (one) ends in ㄹ, and 연대 starts with 여.
• 먹을 엿 (taffy to eat) → [머글렫]: 먹을 ends in ㄹ, and 엿 starts with 여.

A pause between the words cancels the change. In careful, word-by-word reading, 할 일 can be heard as [할 일], but in normal speech [할릴] is standard. Not every candidate word follows the rule, though, as the next section explains.

Is It Always Applied?

The ㄹ case is applied in standard speech whenever the meaning test is passed, but a small set of words never take it. The best-known exception ending in ㄹ is 송별연 (farewell party), which is [송벼련] with plain liaison. These words are listed in Article 29 under 다만 (however) and collected in Korean N Insertion Exceptions.

Two other situations look similar but are not exceptions. The first is a single word that speakers do not feel as two parts, such as 월요일 (Monday) [워료일] and 일요일 (Sunday) [이료일]. The second is a particle or ending, which is never a meaning word.

The honest limit is that the meaning test is a guide, not a guarantee. For an unfamiliar word, check the bracketed pronunciation in the Standard Korean Language Dictionary (표준국어대사전). The contrast with liaison is clearest in a side-by-side table.

When There Is No Insertion after ㄹ

No insertion happens when the second part is a particle, an ending, or part of a single word. In those cases liaison moves the ㄹ forward as a single flap.

Compare 물이 [무리] and 물약 [물략]. Both start with 물 and a vowel, but only 물약 has a meaning word as its second part. That single check decides between a flap and a long l. The worked example puts every step together.

Worked Example: 서울역

The word 서울역 is 서울 (Seoul) plus 역 (station), and it is spoken [서울력]. It is the most useful example of Korean n insertion with ㄹ for travellers.

1. Split into parts: 서울 / 역.
2. Check the first part: 서울 ends in ㄹ.
3. Check the second part: 역 starts with 여, a trigger vowel.
4. Check the meaning: 역 means station, so the boundary allows insertion.
5. Insert ㄴ: 역 → [녁].
6. Apply lateralization: ㄴ after ㄹ becomes ㄹ, so [녁] → [력].
7. Say it in one breath: [서울력], with the tongue held on the ridge from 울 into 력.

You will know it worked when you hear "ul" clearly in the second syllable and a long l before "yeok". If the second syllable sounded like "u", you used liaison. The mistakes below explain the usual problems.

Common Learner Mistakes

Learners often handle the ㄹ case with only one of the two rules. The mistakes below come from that habit.

• Mistake 1: liaison only. Learners often say 서울역 as *[서우력]. Actually 역 is a meaning word, so a ㄴ is inserted first and becomes ㄹ: [서울력].
• Mistake 2: insertion only. Learners who know n-insertion often say *[서울녁]. Actually ㄴ cannot follow ㄹ in Korean speech, so it becomes ㄹ.
• Mistake 3: inserting before a particle. Learners sometimes say 물이 as *[물리]. Actually 이 is a particle, so liaison applies: [무리].
• Mistake 4: flapping the long l. Learners often produce a quick r in [알략]. Actually [ㄹㄹ] is a held l, because the tongue stays on the ridge.
• Mistake 5: inserting in 월요일. Learners often say *[월료일]. Actually 월요일 is one word, so liaison gives [워료일].

Rule of thumb: ㄹ plus a meaning word starting with i or y gives a long l. The practice set tests this rule and its traps.

Practice and Answer Key

Write the spoken form of each item in brackets. Three items do not take insertion.

1. 서울역
2. 알약
3. 물약
4. 휘발유
5. 솔잎
6. 할 일
7. 물이
8. 지하철역
9. 월요일
10. 불여우
11. 서울에

Answer key

1. 서울역 → [서울력]
2. 알약 → [알략]
3. 물약 → [물략]
4. 휘발유 → [휘발류]
5. 솔잎 → [솔립]
6. 할 일 → [할릴]
7. 물이 → [무리] (particle: liaison)
8. 지하철역 → [지하철력]
9. 월요일 → [워료일] (one word: liaison)
10. 불여우 → [불려우]
11. 서울에 → [서우레] (particle: liaison)

Ten or eleven correct means the chain is secure. If you missed 7, 9 or 11, go back to the meaning test before practising the long l.

Where to Go Next

The next lesson, Korean N Insertion Exceptions, lists words such as 송별연 and 6·25 that refuse the rule, and words with two standard forms. Return to the N-Insertion section for the full sequence, or review the n-insertion rule if the meaning test still feels uncertain.

This lesson covers Korean n insertion with ㄹ in standard Seoul speech, inside compounds and across a space. It does not cover the full exception list, regional pronunciation, or loanwords. The audio shows one standard pronunciation, and real speakers vary in speed.

Frequently Asked Questions

How do you say 서울역? Say [서울력], seo-ul-lyeok. 서울역 (Seoul Station) is 서울 plus 역 (station). Because 역 is a word with its own meaning and starts with 여, a ㄴ is added, and that ㄴ becomes ㄹ after the ㄹ of 서울. The result is a long l followed by yeok. Saying [서우력] is a common learner error.

Is 알약 [알략]? Yes. 알약 (pill, tablet) is [알략]. The parts are 알 (a small round thing) and 약 (medicine). N-insertion adds ㄴ before 약, and lateralization turns that ㄴ into ㄹ after 알. Revised Romanization writes allyak; the official romanization rules use this very word as an example.

Is 지하철역 [지하철력]? Yes. 지하철역 (subway station) is [지하철력] in standard pronunciation. 지하철 (subway) ends in ㄹ and 역 (station) starts with 여, so the inserted ㄴ becomes ㄹ. You will hear the same pattern in 전철역 [전철력]. Station words are the most common place learners meet this rule.

What about 물약? 물약 (liquid medicine) is [물략], following the same two steps as 알약. Compare 물이 (water, as subject), which is [무리]: 이 is a particle, so liaison applies and nothing is inserted. The meaning of the second part decides which rule you use.

Why does 휘발유 end in 류? 휘발유 (gasoline) is 휘발 (evaporation) plus 유 (oil). The second part 유 triggers n-insertion, and the inserted ㄴ follows ㄹ, so it becomes ㄹ. The spoken form is [휘발류]. Compare 식용유 (cooking oil) [시굥뉴], where the ㄴ stays ㄴ because the part before it ends in ㅇ.