Japanese Sa and Mi: Turning Adjectives into Nouns, with Examples

The measuring tape and the tongue: one idea for sa and mi

Stand at a market stall. The seller puts tomatoes on a scale and reads off the weight. That reading is sa: omosa, a position on a scale that anyone can check. Then the seller hands you a slice. What you notice in your mouth is mi: amami, a quality that is there in the tomato and that you sense.

Keep both halves of the picture. Sa answers how much. Mi answers what you can feel in it. When you meet a new word ending in sa or mi, ask which of the two questions it answers, and the meaning usually follows.

How sa and mi nouns are built

The formation is the same for both endings. Remove what makes the word an adjective, the final i or the na, and attach sa or mi to what is left. The result is an ordinary noun. It takes particles, and the thing that has the quality is linked to it with no.

The last row shows how far sa reaches. Anything that conjugates like an i-adjective can take it, including yasui and nikui endings, rashii, and even the tai form in set expressions. One irregular word is worth knowing: the usual noun from shizuka is shizukesa, stillness, though shizukasa also exists.

Sa for degree: takasa, omosa, hirosa, benrisa

The most common sa words are the dimensions: nagasa, length, takasa, height, hirosa, area, ōkisa, size, omosa, weight, hayasa, speed, fukasa, depth. You need them whenever you ask how big, how long or how heavy. Flat hunting is a good example. You are standing in an empty room with an estate agent, and nearly every question you have is a sa question.

Sa does not need a number to be a degree. Benrisa, taisetsusa and yasashisa cannot be read from an instrument, but you can still have more or less of them, and that is enough.

Sa for weather, feelings and good points

Once you know the pattern, sa lets you talk about qualities as things: the heat of summer, the kindness of a friend, the good side of a town. A colleague who has just moved from Hokkaido to Tokyo is comparing the two over lunch.

Mi for what you sense: amami, itami, tsuyomi, yowami

Why can only some adjectives take mi? Because mi needs a quality that can be sensed as present inside something, the way a flavour is present in food. That limits it to a few fields: tastes, bodily sensations, emotions, colours, and the physical feel of objects. Size and price are readings, not sensations, so ōkii and yasui have no mi form.

Mi words are usually used with ga aru, to have, or with verbs of feeling and increasing. At a clinic, the doctor asks about itami, not itasa, because pain is something you feel in your body, not a figure on a chart.

The fifth sentence uses both endings. Tsuyomi is a strong point you possess, and nebarizuyosa, from nebarizuyoi, is the degree of a trait. A few common words, tanoshimi, kanashimi and kurushimi, look like mi nouns and can also be explained as noun forms of the verbs tanoshimu, kanashimu and kurushimu. Either way, they behave like the rest of the group.

One ending changed: sa and mi side by side

When an adjective takes both endings, the two nouns divide the work between measurement and sensation. Each pair below differs in the ending alone.

Look at what follows each noun. Sa nouns appear with numbers, with wa plus a description of level, and with verbs like hakaru, to measure. Mi nouns appear with ga aru and ga tsuyoi. You can often predict the ending from the rest of the sentence.

Mi also drifts into figurative meaning more easily than sa. Omomi is the gravity of a promise, fukami the depth of a character, atatakami the warmth of an atmosphere.

Beyond the basics: sa versus no and koto

The closest neighbours of sa are the nominalisers no and koto, which a separate post covers in full. They turn a whole clause into a noun, so the adjective stays an adjective and keeps its subject with ga. Sa turns the adjective itself into a noun, so the owner of the quality takes no. Nedan ga takai no and nedan no takasa both come out in English as how expensive it is, but the first means the fact that the price is high, and the second means the level of the price.

Choose no or koto when you are reacting to a fact. Choose sa when you are talking about the degree. Written Japanese also has a set pattern with sa for cause: amari no plus a sa noun plus ni, because of the sheer degree.

Common mistakes with sa and mi

The first mistake is keeping the i: takaisa, samuisa. Learners produce it by adding sa to the dictionary form. It is wrong. The i must go: takasa, samusa.

The second is iisa for goodness. It follows the rule, but ii is irregular and returns to its old stem. Say yosa.

The third is inventing mi words. Ōkimi and benrimi are wrong, because size and convenience are not sensations. When in doubt, use sa: ōkisa, benrisa.

The fourth is the wrong particle before the noun. Heya ga hirosa wa dono kurai desu ka is wrong, because hirosa is a noun and must be linked with no. Say heya no hirosa.

The fifth is sa where the body is speaking. At a clinic, itasa ga arimasu sounds odd. The established word for pain as a symptom is itami, so say itami ga arimasu. In the same way, tanoshimi is something you look forward to, while tanoshisa is how enjoyable something is, so tanoshimi ni shite imasu cannot be replaced by tanoshisa.

• Drop i or na first, then add sa
• Ii becomes yosa
• No mi form in the dictionary: use sa
• Owner of the quality takes no, not ga
• Symptoms and tastes: itami, kayumi, amami

How sa and mi sound in real conversation

Sa nouns are neutral in politeness and at home in both speech and writing. In casual talk, speakers often prefer the adjective itself, saying takai ne where a report would say takasa. Sa nouns become more frequent as the language gets more formal or more precise: product descriptions, news, presentations.

Mi words are everyday vocabulary in food writing, medicine and business, and tsuyomi and yowami are standard in interviews. You may also meet playful new mi words online, where younger speakers attach mi to unexpected words for effect. That is slang and it changes quickly, so treat it as something to recognise, not to copy in polite company.