Sound Changes I: Nasalization and ㄹ Assimilation

Why sounds change

Some consonant pairs are hard to say one after the other. For example, try saying 국 and then 물 quickly: 국물 (soup). Your tongue must make a hard stop for ㄱ and then immediately switch to a nasal sound for ㅁ. Korean solves this by making the first sound nasal too: [궁물]. This kind of change is called 비음화, nasalization.

The spelling never changes. You still write 국물. Only the pronunciation adapts. These changes are not slang or lazy speech. They are part of the Standard Pronunciation, and every Korean speaker makes them, including news readers.

The pattern is logical

Look at the table again. ㄱ and ㅇ are both made at the back of the mouth. ㄷ and ㄴ are both made with the tongue tip. ㅂ and ㅁ are both made with the lips. So the mouth stays in the same place and only lets air through the nose.

Remember that this works on the final sound, not the letter. 꽃 is said [꼳], so in 꽃말 (the meaning of a flower) the [ㄷ] becomes [ㄴ]: [꼰말]. 있는 is [읻] + 는, so it becomes [인는]. Always ask yourself first: which of the seven sounds is this batchim?

ㄹ becomes ㄴ after ㅁ and ㅇ

ㄹ does not follow ㅁ or ㅇ easily. When ㄹ comes right after a final ㅁ or ㅇ, it is pronounced [ㄴ]. A famous example is the Seoul street and area name 종로, which is said [종노]. Others are 음료 (drink) [음뇨] and 정류장 (bus stop) [정뉴장].

This can join with nasalization. In 국립 (national), the ㄹ after ㄱ becomes [ㄴ], and then that new ㄴ makes the ㄱ nasal: [궁닙]. The same happens in 협력 (cooperation) [혐녁] and 독립 (independence) [동닙].

ㄹ assimilation: ㄴ becomes ㄹ

When ㄴ and ㄹ meet, in either order, the ㄴ usually becomes [ㄹ], and you hear a long [ㄹㄹ], a clear double l. This is called 유음화, ㄹ assimilation.

ㄴ + ㄹ: 신라 (Silla, an ancient Korean kingdom) is [실라]. 연락 (contact) is [열락]. 한라산 (Hallasan, the mountain on Jeju Island) is [할라산].

ㄹ + ㄴ: 설날 (Lunar New Year) is [설랄]. 물냉면 (cold buckwheat noodles in broth) is [물랭면].

There are a few words, mostly long compounds where a word is joined to a suffix like 량 (amount) or 란 (column), where ㄹ becomes [ㄴ] instead: 생산량 (amount produced) is [생산냥]. These are less common. If a word looks unusual, check its pronunciation in the dictionary.