I-Adjectives

イ形容詞・いAい

1. Definition

I-adjectives (い形容詞) are a type of adjective in Japanese that express states, qualities, or feelings, typically ending in "い". They can directly modify nouns and can also function as predicates.

2. Characteristics

Ending: All I-adjectives end with the syllable "い".
Conjugation: I-adjectives change form depending on the grammatical context.
Functionality: They can modify nouns or serve as predicates in sentences.

3. Structure

Form	Example	Explanation
Basic Form	高い (たかい)	An adjective meaning "tall".
Negative Form	高くない (たかくない)	Means "not tall".
Past Form	高かった (たかかった)	Means "was tall".
Past Negative Form	高くなかった (たかくなかった)	Means "was not tall".

4. Usage Explanation

Modifying Nouns: I-adjectives can be placed directly before a noun to modify it.
Example: 美しい花 (うつくしいはな, "beautiful flower")
As Predicates: When used as predicates in a sentence, they can appear in their basic form or in a conjugated form.
Example: この花は美しい。 (このはなはうつくしい。 "This flower is beautiful.")

5. Example Sentences

その映画は面白いです。
(そのえいがはおもしろいです。 "That movie is interesting.")
彼は背が高い。
(かれはせがたかい。 "He is tall.")
今日は寒くない。
(きょうはさむくない。 "It is not cold today.")
このケーキは甘い。
(このけーきはあまい。 "This cake is sweet.")
彼女は優しかった。
(かのじょはやさしかった。 "She was kind.")

6. Points to Note

Conjunctions: Pay attention to how they combine with other particles; they cannot be replaced arbitrarily.
Conjugation Rules: Familiarize yourself with the various conjugation rules, especially for negative and past forms.

7. Summary

I-adjectives are an important type of adjective in Japanese. Mastering their characteristics and usage is key to improving Japanese expression. Through ample practice and application, communication can become more fluent and natural.