The Moraic ん and Nasal Assimilation

The kana ん (katakana ン) is one of the strangest and most useful sounds in Japanese. It is the only consonant that can stand alone as a full mora, and its precise pronunciation is not fixed: it changes depending on the sound that comes right after it — [m], [n], [ŋ], or even a nasalized vowel. English speakers tend to make two mistakes here at once: they give ん a single rigid English "n," and — more damagingly — they fail to count it as a beat. This page fixes both.

The good news, and the distinguishing insight of this page, is that you do not need to memorize the assimilation table below in order to speak. Native speakers do not consciously apply it; it happens automatically because the human mouth takes the path of least resistance. Your only real job is to hold ん as its own full beat and let your mouth relax into the next sound — the correct variant falls out on its own.

ん is a full mora

Before anything else: ん takes up one whole beat. にほん（日本, "Japan"）is three morae — に・ほ・ん — not two. しんぶん（新聞, "newspaper"）is four: し・ん・ぶ・ん. This is where English intuition betrays you, because in English a final or pre-consonant "n" is just a quick tail on the previous syllable ("Japan" is two syllables, "Nippon" feels like two). In Japanese, ん gets equal time with every other beat.

Notice how many ん-beats live in that sentence — nihoN, ichineNkaN, beNkyō — each one a held nasal beat.

The four environments

The exact sound of ん is determined by the following consonant. Here is the full picture; read it to understand what your mouth is doing, not to memorize it.

[m] before b, p, m

When the next sound needs closed lips (b, p, m), ん assimilates all the way forward to [m] — your lips are already shutting for the coming consonant, so the nasal comes out as [m]. This is why traditional Hepburn spells 新聞 as shimbun and 散歩（さんぽ, "a walk"）as sampo: the spelling reflects the real sound.

[n] before t, d, n, s, z, r

Before consonants made with the tongue-tip (t, d, n, s, z, r), ん is a plain [n] — the closest to the English sound, which is why learners over-apply it.

[ŋ] before k, g

Before k or g, ん becomes a velar [ŋ] — the "ng" sound at the end of English sing — because the tongue is already lifting at the back of the mouth for the coming k/g. It never touches the ridge behind your teeth here.

Nasalized vowel before vowels, y, w, h, or a pause

This is the environment English speakers miss most. Before a vowel, before y/w/h, or at the end of a word, ん does not make firm contact anywhere. It becomes a long nasal hum — often described as a nasalized version of the surrounding vowel, or a uvular [ɴ] deep in the throat. Crucially, it stays a full beat and keeps the following vowel separate.

The apostrophe in hon'ya（本屋, "bookstore"）and ren'ai（恋愛, "romance"）is not decoration — it marks that ん is its own beat before the vowel. Without it, 本屋 hon'ya would blur into a nonexistent "honya," and 禁煙（きんえん, "no smoking"）kin'en would collapse into "kinen"（記念, "commemoration") — a real word with a completely different meaning.

Why you should not memorize the table

Here is the liberating part. The four variants above are all the easiest thing your mouth can do given the next sound. Your lips are already closing for b, so [m] is free. Your tongue is already at the back for k, so [ŋ] is free. Native speakers never think "b is coming, switch to [m]" — physics does it for them. If you simply commit to (1) giving ん a full beat of nasal hum and (2) relaxing toward the next sound rather than forcing an English "n," you will produce the right variant automatically almost every time. For how ん fits into the writing system and its katakana partner ン, see The Kana ん / ン.

Common mistakes

Mistake 1: Not counting ん as a beat. The single most important error. English speakers say にほん in two beats. It is three.

Mistake 2: A fixed English [n] everywhere. Pronouncing 新聞 with a crisp tongue-tip "n" ("shin-bun") instead of letting the lips close for [m] ("shimbun"). It is not wrong enough to block understanding, but it is instantly identifiable as a foreign accent.

Mistake 3: Merging ん into a following vowel. Reading きんえん as "ki-nen" instead of kin'en — three-plus beats with ん held separately. This actively changes meaning (禁煙 "no smoking" vs. 記念 "commemoration").

Mistake 4: Over-thinking the assimilation in real time. Trying to consciously select [m]/[n]/[ŋ] mid-sentence makes you halting and, ironically, more error-prone. Trust your mouth; just hold the beat.

Mistake 5: Clipping word-final ん. At the end of ほん（本, "book") or みかん, learners cut the nasal short. Let it ring for a full beat with the tongue relaxed and the sound resonating in the nose.

Key takeaways

• ん is a full mora — always give it its own beat.
• Its sound assimilates automatically: [m] before b/p/m, [n] before t/d/n/s/z/r, [ŋ] before k/g, and a nasal vowel before vowels, y, w, h, or a pause.
• You do not memorize this — you hold the beat and let your mouth relax into the next sound.
• Before a vowel, keep ん separate (kin'en, not "kinen"); the beat carries meaning.