Korean ㅎ Rules and ㄴ Insertion: 좋다 Is [조타], 색연필 Is [생년필]

The letter ㅎ is often silent or merged in Korean. 좋다 is pronounced [조타], with ㅎ and ㄷ combined into ㅌ, while 낳은 is [나은], with the ㅎ gone completely. A second surprise runs the other way: 색연필 (colored pencil) is pronounced [생년필], with an ㄴ that is not in the spelling. Article 12 and Article 29 of the Standard Pronunciation (표준 발음법), published by the National Institute of Korean Language (NIKL), cover both. As of October 2026, the version on the NIKL site is the one in force since March 28, 2017.

The overall approach comes from Article 1: Standard Pronunciation follows the real pronunciation of standard words, balanced against the tradition and logic of the language. The ㅎ rules are a good example, since ㅎ is weak in real speech and drops out easily. The commentary on Article 2 notes that ㅎ is hard to class as a plain or aspirated consonant, because it merges into aspirated sounds next to some consonants yet disappears in words like 좋은 [조은] and 낳아 [나아].

1. Article 12: four rules for ㅎ

A final ㅎ (including ㄶ and ㅀ) behaves differently depending on what follows it.

1.1. 1. Before ㄱ, ㄷ or ㅈ: merge into an aspirated sound

The two sounds combine into ㅋ, ㅌ or ㅊ.

• 놓고 → [노코]
• 좋던 → [조턴]
• 쌓지 → [싸치]
• 많고 → [만코]
• 않던 → [안턴]
• 닳지 → [달치]

The same merge happens in the other order. When ㄱ, ㄷ, ㅂ or ㅈ comes first and ㅎ follows, the pair also becomes an aspirated sound: 각하 [가카], 먹히다 [머키다], 밝히다 [발키다], 좁히다 [조피다], 앉히다 [안치다]. The commentary gives 싫증 as a notable exception to the first pattern: it is [실쯩], not [실층].

1.2. 2. Before ㅅ: the ㅅ becomes tense

After ㅎ (including ㄶ and ㅀ), ㅅ is pronounced [ㅆ]: 닿소 [다쏘], 많소 [만쏘], 싫소 [실쏘].

1.3. 3. Before ㄴ: the ㅎ becomes ㄴ

After a plain ㅎ, ㄴ follows and the ㅎ is read as [ㄴ]: 놓는 → [논는], 쌓네 → [싼네]. After ㄶ and ㅀ, the ㅎ is simply not pronounced: 않네 → [안네], 않는 → [안는], 뚫네 → [뚤네], which then becomes [뚤레] under the ㄴ-and-ㄹ rule.

1.4. 4. Before a vowel: the ㅎ disappears

When an ending or suffix that starts with a vowel follows, the ㅎ is silent:

• 낳은 → [나은]
• 놓아 → [노아]
• 쌓이다 → [싸이다]
• 많아 → [마나]
• 않은 → [아는]
• 싫어도 → [시러도]

By this rule, 좋아 is [조아].

2. How romanization writes the ㅎ merge

For the aspirated merges, the NIKL romanization rules say to write the result of the change. The official examples are 좋고 [조코] → joko, 놓다 [노타] → nota, 잡혀 [자펴] → japyeo and 낳지 [나치] → nachi.

There is one exception. For nouns, when ㅎ follows ㄱ, ㄷ or ㅂ, the ㅎ is written out: 묵호 is Mukho and 집현전 is Jiphyeonjeon.

3. Article 29: when a ㄴ appears

In compound and derived words, an ㄴ is added when the first part ends in a consonant and the second part begins with 이, 야, 여, 요 or 유. They are pronounced [니], [냐], [녀], [뇨] and [뉴]. The official examples:

In several of these, the added ㄴ then triggers nasalization of the sound before it. 꽃잎 is first [꼳닙], then [꼰닙]; 색연필 is [색년필], then [생년필].

3.1. If the first part ends in ㄹ

The added ㄴ is pronounced [ㄹ]. Examples: 들일 [들릴], 솔잎 [솔립], 물약 [물략], 서울역 [서울력].

3.2. Across a space

The rule applies when two words are said as one phrase: 한 일 [한닐], 옷 입다 [온닙따]. The official text also lists a few exceptions, such as 6·25 [유기오] and 송별연 [송벼련].

3.3. Romanization of the added ㄴ

The NIKL romanization rules say that when ㄴ or ㄹ is added, the written form follows the sound. Their examples are 학여울 [항녀울] → Hangnyeoul and 알약 [알략] → allyak. Following the same rule, 색연필 is written saengnyeonpil.

4. Putting it together

Here is a quick way to sort a word with a final ㅎ.

1. If a vowel follows, the ㅎ is silent: 놓아 [노아].
2. If ㄱ, ㄷ or ㅈ follows, the pair merges into ㅋ, ㅌ or ㅊ: 놓고 [노코].
3. If ㅅ follows, the ㅅ is tense: 닿소 [다쏘].
4. If ㄴ follows, the ㅎ becomes ㄴ or drops out: 놓는 [논는], 않는 [안는].

For ㄴ insertion, the test is the second part of the word. If it starts with 이, 야, 여, 요 or 유 and the first part ends in a consonant, expect an added ㄴ: 맨입 [맨닙].

5. Key takeaways

• Final ㅎ merges with a following ㄱ, ㄷ or ㅈ into ㅋ, ㅌ or ㅊ: 놓고 [노코], 좋던 [조턴].
• Before ㅅ it makes a tense sound, as in 많소 [만쏘], before ㄴ it becomes ㄴ, as in 놓는 [논는], and before a vowel it is silent, as in 낳은 [나은].
• ㄴ is added in compounds when the second part starts with 이, 야, 여, 요 or 유: 맨입 [맨닙], 색연필 [생년필].
• After a ㄹ final, the added ㄴ is pronounced ㄹ: 솔잎 [솔립].
• Official romanization writes the sound: joko, nota, allyak.