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い-adjective conjugation
Definition
The grammar pattern "い-adjective" is used to describe nouns directly without a particle. It is characterized by ending in the suffix "い" and conjugating directly. The negative form is created by dropping the "い" and adding "くない", the past form by dropping the "い" and adding "かった", and the past negative form by dropping the "い" and adding "くなかった". This pattern is commonly used to describe size, shape, and other physical characteristics of nouns.
Structure
| Form | Pattern | Example |
|---|---|---|
| Present form | Drop "い" and add "くない" for negative | 大きな → 大くない |
| Past form | Drop "い" and add "かった" | 大きい → 大きかった |
| Past negative form | Drop "い" and add "くなかった" | 大きい → 大くなかった |
Examples
きのうのテストは難しかった。
kinou no tesuto wa muzushikatta.
Yesterday's test was difficult.
昨日のテストは難しかった。 (yesterday's test was difficult)
この部屋は大きい。
kono heya wa ookii.
This room is big.
この部屋は大きい。 (this room is big)
先週の映画は面白くなかった。
senkyou no eiga wa omoshirokunakatta.
Last week's movie was not interesting.
先週の映画は面白くなかった。 (last week's movie was not interesting)
この本は読みやすい。
kono hon wa yomiyokii.
This book is easy to read.
この本は読みやすい。 (this book is easy to read)
Context
The "い-adjective" pattern is used to describe nouns directly without a particle. It is commonly used to describe size, shape, and other physical characteristics of nouns. The negative form is used to indicate that something is not true, the past form to indicate that something was true in the past, and the past negative form to indicate that something was not true in the past.
Watch out
For example, "大きいな" is incorrect, the correct form is "大きい".
For example, "高いじゃない" is incorrect, the correct form is "高くない".
For example, "大きくなかった" is the past negative form, while "大きくない" is the present negative form.
Strategy
Pay attention to the context and use the correct form of the "い-adjective" pattern. Make sure to drop the "い" and add the correct suffix to form the negative, past, and past negative forms.
In context
Worked examples drawn from JLPT N5 test-style questions. Each sentence shows い-adjective used correctly, with a brief note on what the pattern is doing.
きのうのテストはむずかしかった。
Pattern used: むずかしかった
きのう (yesterday) requires past tense. い-adjective past: drop い → かった. むずかしい → むずかしかった. Adding だった is a common mistake mixing な-adjective conjugation.
この部屋はあつくない。
Pattern used: あつくない
い-adjective negative: drop い → くない. あつい → あつくない. Using じゃない is the な-adjective/noun pattern, not い-adjective.
先週の映画はおもしろくなかった。
Pattern used: おもしろくなかった
先週 (last week) signals past tense, and the negative meaning requires past negative: drop い → くなかった. おもしろい → おもしろくなかった.
Interactive
きのうのテストは______。
Adaptive practice
Our adaptive engine will quiz you on this grammar pattern and track your progress toward mastery.