ㅎ Weakening & Deletion Between Voiced Sounds

The letter ㅎ is the weakest consonant in Korean. When it sits between two voiced sounds — between vowels, or right after a sonorant ㄴ, ㄹ, ㅁ, ㅇ — it has almost nothing to hold onto, and in relaxed, conversational speech native speakers routinely soften it to near-nothing or drop it altogether, letting the surrounding syllables link up. So 전화 ("phone call") is [전화] when you say it slowly and carefully, but [저놔] at normal speaking speed — and both are the same word. Unlike aspiration, which is an obligatory fusion, this ㅎ-weakening (ㅎ 약화·탈락) is a matter of register and tempo: careful speech keeps the ㅎ, casual speech dissolves it. That optionality is exactly why it deserves attention — it is one of the biggest gaps between the Korean in a textbook and the Korean coming out of a real mouth.

Where ㅎ weakens

The environment is "surrounded by voiced sounds." In practice that means two situations:

Between vowels (the ㅎ is the onset of a syllable, with a vowel before and after):

After a sonorant batchim ㄴ, ㄹ, ㅁ, ㅇ (the ㅎ follows one of these and precedes a vowel):

In 전화, the ㅎ sits after the ㄴ batchim of 전; drop it and the ㄴ links straight into 와 → [저놔]. In 결혼, the ㅎ after ㄹ drops and 결 links into 온 → [겨론]. In 은행, the ㅎ after ㄴ drops → [으냉]. The pattern is always the same: pull out the weak ㅎ, and the voiced sounds on either side fuse.

This is optional — a register dial, not a rule

Here is the crucial difference from every other ㅎ process. Aspiration (좋다 → [조타]) and pre-vowel deletion (좋아 → [조아]) are obligatory: there is no careful pronunciation that keeps them separate. ㅎ-weakening is not obligatory. The standard, careful pronunciation of 전화 really is [전화], and in slow, formal, or emphatic speech — a news anchor, a careful self-introduction, someone enunciating a phone number — the ㅎ is fully there. It is at conversational tempo, and in casual register, that speakers let it slide to [저놔]. So you can think of ㅎ-weakening as a dial you turn with your speech rate and formality, not a switch that is always on.

Why it matters most for listening

Because this change is optional, it is easy to produce Korean without it — just keep every ㅎ and you sound careful, maybe a touch formal, but never wrong. The danger is on the listening side. A learner who has only ever heard 전화 as [전화] can completely fail to recognize it when a friend says [저놔] at speed, or 결혼했어요 as [겨로내써요], or 은행 as [으냉]. The word has effectively changed shape. Training your ear to map the reduced forms back to their dictionary spellings is the real payoff of this page — it is why intermediate listeners suddenly "unlock" fast casual speech.

A short field guide to the most common reduced forms you will hear:

Don't confuse it with the other two ㅎ processes

ㅎ shows up in three separate stories, and keeping them apart is what makes this whole area click. Line them up by what the ㅎ is next to:

The two obligatory processes are about grammar — they fire whenever a ㅎ-stem meets an ending, every time. The third is about style — it is a phonetic reduction you speed-adjust. Notice that 좋다 → [조타] and 좋아 → [조아] are the same stem 좋- behaving predictably before a stop versus a vowel; that pair lives on the aspiration page and the ㅎ-batchim-before-a-vowel page. The words on this page (전화, 결혼, 은행) are different: their ㅎ is not a stem-final ㅎ meeting an ending at all — it is a weak intervocalic ㅎ sitting inside a single word.

Don't over-articulate

The mirror-image mistake to mishearing reductions is over-producing the ㅎ. If you punch out a hard, breathy [h] in every 전화 and 은행 and 영화, your speech starts to sound robotic and unnaturally careful — a giveaway that you learned Korean from slow audio. In everyday conversation, letting these ㅎ's go soft is what makes you sound natural. Match the register: crisp ㅎ for formal or emphatic moments, soft-to-absent ㅎ for casual chat.

Common Mistakes

1. Failing to recognize reduced forms while listening. The number-one real-world cost of this rule.

• ✗ hearing [저놔] and not connecting it to 전화 → ✓ 전화 [전화] ~ [저놔]
• ✗ hearing [으냉] and not connecting it to 은행 → ✓ 은행 [은행] ~ [으냉]

2. Over-articulating every ㅎ in casual speech. Sounds stiff and textbook-ish.

• ✗ a hard, breathy [전ㅎ화] in every conversation → ✓ a relaxed [저놔] when chatting

3. Treating [저놔] as an error. It is standard casual pronunciation, not sloppy.

4. Confusing it with obligatory pre-vowel deletion. 좋아 [조아] is a stem-final ㅎ dropping before an ending — always, in every register. 전화 [저놔] is an intervocalic ㅎ weakening — casual only.

5. Assuming the romanization shows the reduction. Revised Romanization writes the careful standard form — 전화 is jeonhwa, 은행 is eunhaeng. The casual reduction lives only in the bracket [저놔].

Key Takeaways

• Between voiced sounds — between vowels, or after ㄴ/ㄹ/ㅁ/ㅇ — ㅎ is weak and, in casual, faster speech, often drops: 전화 [저놔], 결혼 [겨론], 은행 [으냉], 영화 [영와].
• This is optional, a matter of register and tempo — careful speech keeps the ㅎ, so [전화] and [저놔] are the same word.
• It matters most for listening: learn to map the reduced forms back to their spellings.
• Keep it distinct from the two obligatory ㅎ processes: aspiration (좋다 [조타]) and pre-vowel deletion (좋아 [조아]).
• Don't over-articulate ㅎ in casual speech, and don't expect the romanization (jeonhwa) to show the reduction.