くない
Not (Adjective)
Structure
Examples:
おもしろく + ない
新しく + ない
Explanation
To make an い-Adjective negative in Japanese, you will use its conjunctive form and attach ない to the end. The term conjunctive form refers to a form that allows words to connect. For all い-Adjectives, the conjunctive form is made by dropping the final い and adding く instead.
- このスープは辛くない。This soup is not spicy.
- その映画は面白くない。That movie is not interesting.
It is important to know that the ない that attaches to い-Adjectives is a distinct word from the ない used for verb negation. This adjectival ない is, in fact, an い-Adjective itself and behaves like one. Because ません is an auxiliary verb used to make verbs polite and negative, it cannot be attached directly to an い-Adjective.
- 部屋は広くません。The room don't spacious. (Incorrect example, with incorrect English to match!)
- 部屋は広くありません。The room is not spacious. (Natural Japanese)
As shown in the example above, the correct method is to first connect the adjective to the verb ある, which is then made negative with the auxiliary verb ません. This combination creates the polite negative form.
Caution
Similar to other い-Adjectives, you should never follow ない with だ. Adding です is permissible for a conversational, semi-polite tone, but this is generally restricted to spoken Japanese.
Examples
この時計は高くないです。
This watch is not expensive.
今日は忙しくない。
I'm not busy today.
このカレーは辛くないです。
This curry is not spicy.
大きくない犬。
A dog that is not big.
天気は悪くないです。
The weather is not bad.
重くない箱。
A box that is not heavy.
私の部屋は広くありません。
My room is not spacious.
その映画は怖くない。
That movie is not scary.
彼の成績はよくありません。
His grades are not good.
私は眠くない。
I am not sleepy.
この本はつまらなくない。
This book is not boring.
この試験は優しくありません。
This exam is not easy.