さ (adjective nominaliser)

• Reading: さ
• Romaji: sa
• Formation: Adj-い stem + さ / Na-adj stem + さ

Meaning

A suffix that creates a noun from an adjective by attaching to its stem, expressing the degree or measurable quality of that adjective. It is similar to English suffixes '-ness' or '-ity,' as in 'height' from 'high' or 'depth' from 'deep.'

さ attaches to the stem of い-adjectives (remove い, add さ: 高い→高さ 'height') and to the stem of な-adjectives (remove な, add さ: 静かな→静かさ 'quietness'). The resulting noun refers to the measurable degree or extent of that quality. This suffix is particularly common with adjectives describing physical properties, dimensions, and measurable qualities: 長さ 'length,' 広さ 'area/spaciousness,' 便利さ 'degree of convenience.' A similar suffix み also creates nouns from adjectives, but み often implies a subjective sensation or subtle quality (温かみ 'warmth as a feeling'), while さ is more objective and quantifiable (温かさ 'warmth as a temperature'). Not all adjectives pair equally naturally with さ or み — learners need to acquire these collocations through exposure.

Examples

1. この山の高さは三千メートルです。 The height of this mountain is three thousand metres.
2. 夏の暑さにはまだ慣れていない。 I'm still not used to the summer heat.
3. 彼の優しさに感動した。 I was moved by his kindness.

Usage Guide

Context: spoken, written, everyday

Tone: descriptive

Do Say

• 日本語の難しさを実感しました。
• この部屋の広さはちょうどいいです。
• 彼女の強さに驚いた。

Don't Say

• この建物の高いさはすごい。(Keeping the い before adding さ — the い must be removed: 高い→高さ) → この建物の高さはすごい。
• 彼の親切のさに感謝しています。(Inserting の between a な-adjective stem and さ — attach さ directly to the stem) → 彼の親切さに感謝しています。

Origin & History

The suffix さ originates from Old Japanese and has been used to derive nouns from adjectives since at least the Nara period. It was already productive in Man'yōshū poetry, where forms like 高さ and 深さ appear in their modern sense.

Cultural Context

Generation: All ages

Social background: Universal