Korean sound-change rules: why 좋아요 sounds like 조아요

Linking: 연음

This is the rule you will use most. When a syllable with a batchim is followed by a syllable that begins with a vowel, the batchim moves over and becomes the first sound of that syllable.

밥을 is written as 밥 + 을 and pronounced 바블. 한국어 is pronounced 한구거. 음악 is pronounced 으막. The written blocks stay put; the sounds slide.

This is also where the original spelling of a batchim comes back to life. On its own, 옷 ends in a stopped ㄷ sound. But in 옷이 the ㅅ moves onto the vowel and is pronounced as a real s: 오시. That is why Korean keeps writing letters that seem to disappear — they are waiting for a vowel.

Linking makes speech faster and smoother, and refusing to link is one of the clearest signals of a text-trained learner. Say the phrase, not the blocks.

ㅎ goes quiet

Between voiced sounds, ㅎ weakens to almost nothing. 좋아요 comes out 조아요. 많이 comes out 마니. 전화 is commonly heard as 저놔.

This is not sloppiness or fast speech — it is how the words are normally said, including in careful speech, and pronouncing a strong h there sounds stilted.

The opposite also happens: when ㅎ meets a plain stop, the two fuse into an aspirated one. 좋다 is pronounced 조타, with the ㅈ and the ㅎ combining into a ㅌ. 축하 becomes 추카. Once you know this rule, a set of common words that looked irregular suddenly makes sense.

Consonants that copy their neighbors

When two consonants meet across a syllable boundary, the first usually adapts to the second.

Before a nasal, a stop becomes a nasal. 감사합니다 is pronounced 감사함니다 — the ㅂ turns into ㅁ because ㄴ follows. This is one of the first words you will ever say in Korean and it is affected.

ㄴ and ㄹ next to each other both go to l: 신라 is 실라, 설날 is 설랄.

After a stop batchim, a following plain consonant tenses: 학교 is pronounced 학꾜, 있다 is 읻따. This tensing is regular and automatic, and it is a reason not to over-analyze the plain, tense and aspirated distinction from spelling alone — the surrounding sounds change what actually comes out.

Words to practice

Linking first: 좋아요, 밥을, 음악, 한국어. Say each one as one connected chunk, at speaking speed, and check that no syllable boundary survives where a vowel follows a batchim.

Then the ㅎ set: 좋아요 against 좋다. The same word stem produces 조아요 and 조타 — one where the ㅎ vanishes, one where it fuses.

Then assimilation: 감사합니다, 같다, 학교, 있다. 같다 is a good test because two rules apply at once: the ㅌ becomes a stopped ㄷ, and the following ㄷ tenses to ㄸ, giving 갇따.

Then a full phrase, because the rules apply across word boundaries too, not only inside words: 한국어를 공부해요. Say it as one connected stretch and let the batchim slide onto each following vowel.

Read each of these out loud from the surface pronunciation, not from the spelling. Writing the pronounced form next to the written form in your notes for a week is usually enough to break the habit — after that your eye starts applying the rules automatically as you read.

What to listen for

Listen for gaps. If you can hear the seams between syllable blocks, you are reading rather than speaking. Korean phrases run together.

Listen for a surviving h in 좋아요 and 많이. If you can hear it, soften it until it disappears.

And listen for evenness. Korean gives each syllable roughly equal weight, so applying English stress — hitting one syllable and crushing the rest — makes even perfectly formed sounds land wrong. Practice at a steady pace before you practice fast.

TonePerfect scores the surface pronunciation, which is to say what Koreans actually say rather than the letter-by-letter spelling, so linked speech is scored as linked speech. Your sounds come back ranked weakest-first to tell you what to drill. One honest note about the consonant system while you are here: word-initially, even native speech hardens plain consonants toward tense, so the app does not claim to grade the plain, tense and aspirated three-way contrast at the start of a word. Practice that contrast in the middle of words, where it is clearest, and use the puff of air on aspirated consonants as your most reliable anchor.

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