Korean Sino-Korean Tensification: Sounds, Rules and Examples

What you will learn

• Say 갈등, 발달, 일시, 물질 and 발전 with tense consonants after ㄹ.
• Name the three consonants the rule affects and the two it leaves alone.
• Recognise a likely Sino-Korean word and check it in a dictionary.
• Spot the repeated-character exception and native words that never change.

Before you start: you know what a tense consonant is and how a stop final makes the next consonant tense, from Korean Tensification After Batchim. Time: about 25 minutes with audio.

Key Facts

• In Sino-Korean words, ㄷ, ㅅ and ㅈ after a final ㄹ are pronounced tense: 갈등 is [갈뜽], 일시 is [일씨] and 물질 is [물찔].
• ㄱ and ㅂ after ㄹ stay plain in the same words: 발견 is [발견] and 일부 is [일부].
• The rule is Article 26 of the Standard Pronunciation Rules (표준 발음법).
• Words made of a repeated hanja syllable are exceptions: 허허실실 is [허허실실] and 절절하다 is [절절하다].
• Native Korean verb forms do not follow the rule: 알지 is [알지] and 놀자 is [놀자].
• Revised Romanization does not show tensing caused by a neighbouring sound, so 갈등 is written galdeung.

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 Sino-Korean Tensification?

Korean Sino-Korean tensification is a tensification rule limited by word origin. Tensification (경음화) means a plain consonant is pronounced as its tense partner: ㄷ as ㄸ, ㅅ as ㅆ, ㅈ as ㅉ. A tense consonant is made with a tight throat and no puff of air. Sino-Korean words (한자어) are words built from hanja, the Chinese characters that Korean has borrowed over many centuries.

Most tensification rules depend only on sounds, such as a stop before the consonant. This one also depends on vocabulary: the same letters ㄹ + ㄷ change in a hanja word and stay plain in a native word. That makes it one of the few Korean pronunciation rules where meaning and history matter.

Revised Romanization (RR) does not show tensing caused by a neighbouring sound, so 갈등 is galdeung even though Koreans say [갈뜽]. Learners who read Korean through romanization miss this rule entirely. RR is a learning aid here; the Hangul and the bracketed forms are the reference. The romanization gap is also why so many learners say these words the wrong way.

Why Learners Say "Gal-Deung"

Learners say "gal-deung" because the spelling and the romanization both suggest a plain ㄷ. In English, l followed by d is relaxed, as in "golden". A Korean listener hears plain [갈등] as unusual and may need a moment to recognise the word.

A second problem is that the rule seems to have no sound-based cause. After a stop such as ㄱ, tensing feels natural because the mouth is already closed and tight. After ㄹ, the tongue is relaxed, so learners do not expect any tension.

The solution is to treat the rule as a word-type rule: identify a hanja word, then apply the change. The next section states the rule precisely.

What Does the Rule Do?

The rule makes ㄷ, ㅅ or ㅈ tense when it follows a final ㄹ inside a Sino-Korean word. Article 26 of the Standard Pronunciation Rules (표준 발음법), published by the National Institute of Korean Language (국립국어원), states it with examples such as 갈등 [갈뜽], 발동 [발똥], 절도 [절또], 말살 [말쌀], 일시 [일씨], 갈증 [갈쯩], 물질 [물찔] and 발전 [발쩐].

Check three conditions in order:

1. Is the word Sino-Korean? It must be built from hanja syllables.
2. Does a syllable end in ㄹ? For example 갈, 발, 일 or 물.
3. Does the next syllable start with ㄷ, ㅅ or ㅈ? If so, say ㄸ, ㅆ or ㅉ.

If any condition fails, the consonant stays plain. The third condition is the one that surprises learners most, because two common consonants are left out.

Why Are ㄱ and ㅂ Not Affected?

ㄱ and ㅂ are not affected because Article 26 names only ㄷ, ㅅ and ㅈ. In the same hanja family, 발전 (development) is [발쩐] but 발견 (discovery) is [발견], and 발표 (presentation) has an aspirated ㅍ that does not change. The rule is a list, not a general principle.

A helpful way to remember the list is the tongue. ㄷ, ㅅ and ㅈ are made with the front of the tongue near the ridge behind the teeth, which is where ㄹ is made too. ㄱ is made at the back of the tongue and ㅂ with the lips. This is a memory aid, not the official reason, but it matches the pattern.

The pairs share a first syllable, so the only difference is the consonant that follows. With the condition clear, a longer list builds the habit.

Fifteen Common Words to Practise

The fifteen words below appear constantly in news, school subjects and daily conversation. Each one is Sino-Korean, and each has ㄹ before ㄷ, ㅅ or ㅈ.

Expert tip: learn these words with their -하다 or -히 forms, because that is how you will say them most. 열심히 is [열씸히], 결정하다 is [결쩡하다] and 실수했어요 (I made a mistake) is [실쑤해써요]. The next question is how to know which words are Sino-Korean in the first place.

How Can You Tell a Sino-Korean Word?

A Sino-Korean word can usually be identified by three signs, and a dictionary confirms it. No sign is perfect on its own, but together they are reliable.

• Each syllable has a meaning you meet elsewhere. 발 (發, emit) appears in 발전, 발달, 발생 and 발표, always with a sense of starting or coming out.
• The word is often a formal noun that takes 하다. 발전하다, 결정하다 and 활동하다 are typical.
• The dictionary shows hanja. The Standard Korean Language Dictionary (표준국어대사전) lists 갈등 with its characters 葛藤 and its pronunciation [갈뜽].

Sino-Korean words are especially frequent in formal, academic and news vocabulary, which is where most ㄹ + ㄷ ㅅ ㅈ words come from. Learning common hanja syllables makes the rule much easier, and the Sino-Korean words lesson and the Hanja section are the places to start. Words that are not Sino-Korean behave differently, as the next section shows.

Native Words That Look Similar

Native Korean words with ㄹ before ㄷ, ㅅ or ㅈ do not follow this rule. The clearest cases are verb stems ending in ㄹ plus an ending: 알지 (you know) is [알지], 놀자 (let's play) is [놀자], 살다 (to live) is [살다] and 말다 (to stop) is [말다].

Some native compounds do become tense, but for a different reason. 술집 (bar) is [술찝] and 물고기 (fish) is [물꼬기] because of the compound rule linked to 사이시옷, the "in-between ㅅ" of compound nouns. That rule affects ㄱ and ㅂ too, which is one way to tell it apart. The overview in the tensification rules shows all five triggers side by side. Even within Sino-Korean words, there is one exception group.

Which Words Are Exceptions?

Sino-Korean words made of a repeated syllable are exceptions, and they keep the plain consonant. Article 26 gives 허허실실 (虛虛實實, a strategy of feints) as [허허실실] and 절절하다 (切切-, heartfelt) as [절절하다]. In these words the second 실 or 절 is the same character as the first.

The reason is that a repeated syllable is felt as a copy of the first, and the copy keeps its original sound. A learner at B1 rarely meets these words, so the exception matters less in practice than the native-word contrast above. A more practical question is how far the rule can be trusted.

Is the Rule Reliable?

The rule is reliable inside Sino-Korean words: if all three conditions are met and the word is not a repeated syllable, expect the tense sound. Prefixed words follow it too, such as 몰상식 (lack of common sense) [몰쌍식].

The limit is that the rule needs knowledge the spelling does not show. Two words can look alike and differ only in origin, and loanwords from English, such as 필드 (field) [필드], are outside the rule. For any word you are unsure of, look up the bracketed pronunciation in the Standard Korean Language Dictionary. The worked example applies the full check to one word.

Worked Example: 갈등

The word 갈등 (conflict) is the hanja 갈 (葛, kudzu vine) plus 등 (藤, wisteria), two climbing plants whose tangled stems gave the word its meaning. It is spoken [갈뜽].

1. Check the origin: 갈등 is Sino-Korean; the dictionary lists 葛藤.
2. Find the final ㄹ: 갈 ends in ㄹ.
3. Check the next consonant: 등 starts with ㄷ, one of the three affected consonants.
4. Check for an exception: the two syllables are different characters, so the repeated-syllable exception does not apply.
5. Apply the rule: ㄷ becomes ㄸ, so 등 is said [뜽].
6. Say the whole word: [갈뜽], with the ㄹ held briefly and a tight, breathless ㄸ.

You will know it worked when there is no puff of air after the ㄸ and the throat feels tight at the start of the second syllable. If the second syllable sounds like English "dung", the consonant is still plain. The mistakes below show where learners usually go wrong.

Common Learner Mistakes

Learners often trust the spelling or apply the rule too widely. The mistakes below come from those habits.

• Mistake 1: plain consonants in hanja words. Learners often say 발전 as *[발전]. Actually ㄹ + ㅈ in a Sino-Korean word is tense: [발쩐].
• Mistake 2: tensing ㄱ and ㅂ. Learners who have just learned the rule often say 발견 as *[발껸]. Actually the rule covers only ㄷ, ㅅ and ㅈ, so 발견 is [발견].
• Mistake 3: tensing native verbs. Learners often say 알지 as *[알찌]. Actually 알다 is a native verb, so its endings stay plain: [알지].
• Mistake 4: trusting romanization. Learners often read galdeung as written. Actually RR never shows tensing caused by a neighbouring sound, so the spoken form is [갈뜽].
• Mistake 5: writing the tense letter. Learners often write 갈뜽 in dictation. Actually the spelling stays 갈등, because the change is only in speech.

Rule of thumb: hanja word, ㄹ, then ㄷ ㅅ ㅈ → tense. The practice set includes two traps.

Practice and Answer Key

Write the spoken form of each word in brackets. Three items stay plain.

1. 갈등
2. 발달
3. 일시
4. 물질
5. 발전
6. 발견
7. 결정
8. 알지
9. 실수
10. 일부

Answer key

1. 갈등 → [갈뜽]
2. 발달 → [발딸]
3. 일시 → [일씨]
4. 물질 → [물찔]
5. 발전 → [발쩐]
6. 발견 → [발견] (ㄱ is not affected)
7. 결정 → [결쩡]
8. 알지 → [알지] (native verb: no change)
9. 실수 → [실쑤]
10. 일부 → [일부] (ㅂ is not affected)

Nine or ten correct means the rule is secure. If you missed 6 or 10, revisit the ㄷ ㅅ ㅈ list; if you missed 8, revisit the native-word section.

Where to Go Next

The next lesson, Korean ㄹ Ending Tensification, covers a different ㄹ rule: the future modifier -(으)ㄹ, as in 할 수 있어요 [할쑤이써요], which tenses ㄱ and ㅂ too. Return to the Tensification section to see every trigger in order.

This lesson covers Korean Sino-Korean tensification after ㄹ in standard Seoul speech, its exceptions and its native-word contrasts. It does not cover tensification in compounds (사이시옷), after the future modifier, or after stops. The audio shows one standard pronunciation, and real speakers vary in speed.

Frequently Asked Questions

Why is 발전 [발쩐]? 발전 (development) is a Sino-Korean word made of 발 (發, emit) and 전 (展, unfold). The first syllable ends in ㄹ and the second starts with ㅈ, so Article 26 of the Standard Pronunciation Rules makes the ㅈ tense: [발쩐]. The same pattern gives 발달 [발딸] and 발생 [발쌩].

Is 일정 [일쩡]? Yes. 일정 (schedule) is the hanja 일 (日, day) plus 정 (程, journey), and it is pronounced [일쩡]. The ㄹ of 일 makes the following ㅈ tense. Learners hear the word constantly in phrases like 일정이 있어요 (I have plans) [일쩡이 이써요], so it is a good model word.

Does the rule apply to 말다? No. 말다 (to stop, to not do) is a native Korean verb, not a Sino-Korean word, so its ㄷ stays plain: [말다]. The same is true of 알다 [알다], 살자 [살자] and 놀지 [놀지]. Article 26 is limited to words built from hanja, which is why the word's origin matters.

How do I know a word is Sino-Korean? Check three signs. Each syllable is a reading you meet in other words with a related meaning, such as 발 in 발전, 발달 and 발생. The word is often a formal noun that can take 하다. And the Standard Korean Language Dictionary (표준국어대사전) shows its hanja and its pronunciation in brackets.

Why does 발견 not have a tense sound? 발견 (discovery) is Sino-Korean and has ㄹ before the next syllable, but that syllable starts with ㄱ. Article 26 covers only ㄷ, ㅅ and ㅈ after ㄹ, so the ㄱ stays plain and the word is [발견]. 일부 [일부] and 결과 [결과] stay plain for the same reason.