Short Forms
Verbs and い-adjectives in the affirmative – same as their dictionary forms
な-adjectives and noun + です in the affirmative – replace です with だ
い-adjectives and な-adjectives and noun + ですin the negative – replace ありません with ない
Negative Short Forms
ru-verbs: Take othe final る off and add ない
Ex: 食べる -> 食べない
u-verbs: Take the final –u off and add –anai
Ex: よむ -> よまない
Irregular verbs: する -> しない、くる -> こない
Exception: ある -> ない
There are some points worth noting with negative short forms:
1. The negative short forms of verbs that end with the hiragana う are …わない instead of …あない
2. The vowel changes with the irregular verb くる
3. The verb ある in the negative is ない
Short forms are used to quote someone else, in casual conversations (as signs of intimacy), and in making negative requests.