Sound changes: why 감사합니다 is gamsahamnida

Korean spelling shows the meaning: a word keeps the same letters in every form. The sound, though, changes with the letters around it. The romanisation in this course follows the sound, so once you know these rules you'll see why 감사합니다 is written gamsahamnida and 한국어 hangugeo. The changes are shown only inside a word, never across a space: 몇 월 (myeot wol, which month) is said myeo-dwol.

Any consonant can be a batchim (the letter at the bottom of a block), but at the end of a syllable Korean has only seven sounds: k, n, t, l, m, p and ng. Final k, t and p are not released: the mouth closes and stops, with no puff of air, as in a quick “yep”. So 옷 (ot, clothes), 낮 (nat, daytime) and 꽃 (kkot, flower) all end in the same t sound.

When a block has two final letters, usually only one is said: 닭 (dak, chicken), 값 (gap, price), 앉다 (anda, to sit), 여덟 (yeodeol, eight). Before a vowel, both are heard (see linking, below).

When the next syllable starts with the silent ㅇ, the batchim moves over and is said at the start of that syllable. 한국어 (hangugeo, Korean) is said han-gu-geo, so it is romanised hangugeo, and 먹어요 (meogeoyo, I eat) is meo-geo-yo.

When it moves, the letter gets its full sound back: 옷 is ot, but 옷이 (osi, the clothes, as a subject) is o-si, and 꽃이 (kkochi) is kko-chi. With two final letters, the second one moves: 읽어요 (ilgeoyo, I read), 없어요 (eopseoyo, there isn't). A final ㅇ never moves: 영어 (yeongeo, English) keeps its ng. A final ㅎ disappears (see below).

A final k, t or p sound becomes a nasal when the next syllable starts with ㄴ or ㅁ: k becomes ng, t becomes n and p becomes m. That is why 감사합니다 (gamsahamnida, thank you) is said gam-sa-ham-ni-da, and why every formal -ㅂ니다 or -습니다 ending sounds like -mnida or -seumnida.

ㄹ changes too. After an m or ng sound it becomes n: 음료 (eumnyo, drink), 정류장 (jeongnyujang, bus stop). Next to ㄹ, an ㄴ becomes l: 연락 (yeollak, contact), 설날 (Seollal, Lunar New Year). After a final k or p, ㄹ becomes n and the k or p becomes nasal too: 독립 (dongnip, independence).

In some compound words an extra n sound appears before 이, 야, 여, 요 or 유, and after ㄹ it becomes l: 지하철역 (jihacheollyeok, subway station) is said ji-ha-cheol-lyeok. The romanisation shows this too.

After a final k, t or p sound, a plain ㄱ ㄷ ㅂ ㅅ ㅈ is said tense, like its double letter: 학교 (hakgyo, school) sounds like hak-kkyo and 식당 (sikdang, restaurant) like sik-ttang. The same happens after the ending -(으)ㄹ: 할 수 있어요 (hal su isseoyo, I can do it) sounds like hal ssu isseoyo.

The romanisation does not show tensing, so it writes hakgyo, sikdang and hal su isseoyo. Just remember that a g, d, b, s or j after k, t or p is said hard. Some words tense for no visible reason, such as 문자 (munja, text message), said mun-jja; you'll pick these up by ear.

ㅎ is a weak sound. A final ㅎ is silent before a vowel: 좋아요 (joayo, it's good) is said jo-a-yo, 많이 (mani, a lot) ma-ni, 괜찮아요 (gwaenchanayo, it's fine) gwaen-cha-na-yo. In everyday speech ㅎ also softens between other sounds, as in 전화 (jeonhwa, phone) and 은행 (eunhaeng, bank), but there the romanisation keeps it.

Next to ㄱ ㄷ ㅂ ㅈ, in either order, ㅎ merges with them into the aspirated ㅋ ㅌ ㅍ ㅊ: 좋다 (jota, to be good) is said jo-ta, 어떻게 (eotteoke, how) eo-tteo-ke, 깨끗해요 (kkaekkeutaeyo, it's clean) kkae-kkeu-tae-yo. Before ㄴ, a final ㅎ is said n: 좋네요 (jonneyo, that's nice). One exception: after a noun, the romanisation in this course keeps the h of 하다, as the official rules do inside nouns, so 생각하다 (saenggakhada, to think, from 생각, a thought) is said saeng-ga-ka-da but written saenggakhada.

A final ㄷ or ㅌ followed by 이 (i) turns into ㅈ (j) or ㅊ (ch): 같이 (gachi, together) is said ga-chi, 해돋이 (haedoji, sunrise) hae-do-ji, and 끝이 (kkeuchi, the end, as a subject) kkeu-chi.

All these changes happen by themselves when you speak at a normal pace, so don't learn them as spelling rules. Listen, repeat, and let the romanisation guide you until the Hangul spelling feels familiar.