〜さ (nominalizer)
sa (nominalizer)
By Nihongo PathUpdated
Meaning
-ness (turns an adjective into a noun expressing degree or amount)
Adjective stem + さ makes a noun that names the degree of a quality: 高い → 高さ "height", 優しい → 優しさ "kindness", 便利 → 便利さ "convenience". It works with almost any adjective and is the objective, measurable version. (For the subjective, felt version see 〜み.)
Measurements (長さ, 重さ, 速さ, 広さ), abstract qualities (大切さ, 難しさ, 新しさ), and phrases like 〜の高さに驚く. All registers.
Formation
V = verb, N = noun, A = adjective.
い-adjective stem + さ (高い → 高さ, 寒い → 寒さ)な-adjective stem + さ (便利 → 便利さ, 静か → 静かさ)Irregular: いい / よい → よさ〜さ + を / が / に + verb (大切さを知る, 高さに驚く)
Visual diagram
| Aspect | Type of quality | Range | Example |
|---|---|---|---|
| 〜さ | Objective degree, measurable | Almost any adjective | 深さ (depth: 5 metres), 重さ, 優しさ |
| 〜み | Subjective feel, sensation | Limited set | 深み (a sense of depth), 甘み, 痛み |
Natural examples
この山の高さは三千メートル以上だ。
このやまのたかさはさんぜんメートルいじょうだ。
The height of this mountain is over 3,000 metres.
Measurable: height in metres.
彼の優しさに感動した。
かれのやさしさにかんどうした。
I was moved by his kindness.
Abstract quality: kindness.
大切さが分かった。
たいせつさがわかった。
I came to understand the importance.
Abstract quality: importance.
この問題の難しさは、やってみないと分からない。
このもんだいのむずかしさは、やってみないとわからない。
You won't understand how difficult this problem is until you try it.
難しさ = difficulty (degree).
都会の便利さに慣れると、田舎の生活は不便に感じる。
とかいのべんりさになれると、いなかのせいかつはふべんにかんじる。
Once you get used to the convenience of the city, country life feels inconvenient.
な-adjective + さ: 便利さ.
Similar grammar and the difference
Subjective, sensory nouns from a limited set of adjectives. Compare side by side
Formal property nouns from Sino-Japanese roots (安全性). Compare side by side
〜こと / 〜の
Nominalise whole clauses, not just adjectives (高いこと = the fact that it is expensive).
Common mistakes
- ✗
- 高いさ
- ✓
- 高さ
- Why
- Drop the い before さ.
- ✗
- いさ (from いい)
- ✓
- よさ
- Why
- いい uses its alternate form よい for derivations.
- ✗
- この料理の甘さがある。(meaning 'has a touch of sweetness')
- ✓
- この料理には甘みがある。
- Why
- A felt, subtle quality uses み; 甘さ would be the measured sweetness level.
〜さ can follow compound adjectives: 分かりやすさ, 使いにくさ. Question pattern: どのくらいの高さ / 大きさ. In 読解, 〜の大切さ / 〜の重要さ are common abstract nouns.
JLPT N3 tips
On the exam
- A blank needing a noun from an adjective, especially with a number or degree → さ.
- If the choices contain both さ and み, decide by measurability: metres/kilograms → さ; taste/pain/feeling → み.
- Remember よさ for いい.
Frequently asked questions
What does 〜さ (nominalizer) mean?
-ness (turns an adjective into a noun expressing degree or amount). Adjective stem + さ makes a noun that names the degree of a quality: 高い → 高さ "height", 優しい → 優しさ "kindness", 便利 → 便利さ "convenience". It works with almost any adjective and is the objective, measurable version. (For the subjective, felt version see 〜み.).
How do you form 〜さ (nominalizer)?
い-adjective stem + さ (高い → 高さ, 寒い → 寒さ) / な-adjective stem + さ (便利 → 便利さ, 静か → 静かさ) / Irregular: いい / よい → よさ / 〜さ + を / が / に + verb (大切さを知る, 高さに驚く). V = verb, N = noun, A = adjective.
When is 〜さ (nominalizer) used?
Measurements (長さ, 重さ, 速さ, 広さ), abstract qualities (大切さ, 難しさ, 新しさ), and phrases like 〜の高さに驚く. All registers.
What is the difference between 〜さ (nominalizer) and 〜み?
Subjective, sensory nouns from a limited set of adjectives.
What is the difference between 〜さ (nominalizer) and 〜性?
Formal property nouns from Sino-Japanese roots (安全性).
What is a common mistake with 〜さ (nominalizer)?
Wrong: 高いさ Right: 高さ Drop the い before さ.
Quick check
この橋の（ ）は約二キロある。