Meaning
An adjective stem plus さ makes a noun: 高い → 高さ (height), 便利な → 便利さ (convenience). It names measurements and the degree of a quality.
Formation
- い-adjective: drop い and add さ: 高い → 高さ, 重い → 重さ
- な-adjective stem + さ: 便利 → 便利さ, 大切 → 大切さ
- いい becomes よさ; the result is a noun: 山の高さ
When to use it
- Core use
- Turning a quality into a noun
Example
この山の高さは三千メートルです
This mountain is three thousand meters high.
Important notes
- Pay attention to the word form before the construction and to the particles around it.
Common mistakes
- Do not translate the pattern word for word; first identify its function in the whole situation.