性
-ness, -ity
The suffix 性（せい） is the Japanese equivalent of English suffixes like "-ness," "-ity," or "-nature." It turns a base word into an abstract noun that describes an inherent property or the potential for something to happen.
How It Works
性（せい） is a highly productive nominalizer used to discuss concepts in formal, technical, or academic contexts, though many common words like 可能性（かのうせい - possibility） are used in daily life.
1. Usage and Meaning:
It transforms the base word into a noun representing its nature. For example, 安定（あんてい - stability） becomes 安定性（あんていせい - the property of being stable/stability）.
2. Attachment Rules:
- It attaches to the stems of な-adjectives (e.g., 危険（きけん） → 危険性（きけんせい）).
- It attaches to nouns (e.g., 人間（にんげん） → 人間性（にんげんせい）).
- It almost exclusively attaches to Sino-Japanese words (Kango). You cannot attach it to native Japanese い-adjectives.
3. Nuance of Potential:
Unlike other nominalizers, 性 often implies a 'potential' or 'tendency.' 可能性（かのうせい - possibility） is the most famous example, describing the potential for something to be possible.
4. Comparison with さ and み:
While さ focuses on measurable degrees (like height or weight) and み focuses on subjective, emotional qualities (like warmth or sadness), 性 is used for abstract, objective properties or inherent characteristics.
Examples (4)
- その計画には、まだ実現の可能性があります。
There is still a possibility of realization for that plan.
Word by Word: That plan-in, still realization-of possibility exists.
可能性（かのうせい） is one of the most common uses, meaning 'possibility' or 'potential'.
- この素材は耐久性が高いです。
This material has high durability.
Word by Word: This material-as-for durability-subject-marker high is.
耐久性（たいきゅうせい） refers to the property of being durable.
- 新しい薬の安全性を確認する。
Confirm the safety of the new medicine.
Word by Word: New medicine-of safety-object-marker confirm.
安全性（あんぜんせい） refers to the abstract concept of 'safety' as a property.
- 彼の人間性に感動しました。
I was moved by his humanity (character).
Word by Word: His humanity-by was-moved.
人間性（にんげんせい） refers to a person's nature or character.
Common Mistakes
Attaching 性 to native Japanese (Wago) adjectives.
この花は美し性があります。この花は美しさがあります。性（せい） only attaches to Sino-Japanese compounds. For native adjectives ending in -i, use さ instead.
Confusing 性 with さ when talking about degree.
この山の高性を測る。この山の高さを測る。さ is used for measurable degrees (how high, how heavy). 性 is for abstract properties or the existence of a quality.
How It Connects
Learn This First
The suffix 性 (せい) is used to create abstract nouns that describe a quality, nature, or tendency (similar to '-ity' or '-ness' in English). It is primarily attached to kanji compounds (kango). To use it effectively, learners should be comfortable with kanji-based word formation and the general concept of nominalization in Japanese.
- Kanji basics
Understanding how kanji can be used as suffixes to modify the meaning of a base word is essential for using 性.
Foundations - Noun Modification
性 is a suffix that attaches to nouns or the stems of adjectives to create a new noun, requiring an understanding of how nouns are formed and modified.
Level 1 - さNoun from い-adj
Both さ and 性 are used to turn words into abstract nouns representing qualities; understanding one helps clarify the usage and nuance of the other.
Level 3
Related Patterns
- みNoun from い-adj
み creates nouns that emphasize subjective feeling or emotional depth, contrasting with the formal and technical nature of 性.
Level 3 - 的-ic, -ical
的 turns nouns into adjectives (-like/-ical), while 性 turns them into abstract nouns (-ity/-ness).
Level 3 - 化-ization
化 is a suffix meaning '-ization' (the process of becoming), while 性 describes the resulting state or property.
Level 3 - な-adjectives
性 often attaches to the stems of な-adjectives to create abstract nouns.
Level 1
Words in This Pattern
Practice 性 in Bubblegum
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