鈍い (nibui) conjugation
dull (e.g., a knife), thickheaded, slow (opposite of fast), stupid
鈍い (にぶい, nibui) is an i-adjective. I-adjectives carry their own tense: drop the final い and the endings attach straight to the stem. No だ, no です needed to make a complete sentence.
Conjugation table
| Form | Plain (casual) | Polite (~です) | When you use it |
|---|---|---|---|
| Dictionary / plain | 鈍い nibui | 鈍いです nibuidesu | The form you look up. Also the casual “is ~”. |
| Negative | 鈍くない nibukunai | 鈍くないです nibukunaidesu | “is not ~”. |
| Past | 鈍かった nibukatta | 鈍かったです nibukattadesu | “was ~”. |
| Past negative | 鈍くなかった nibukunakatta | 鈍くなかったです nibukunakattadesu | “was not ~”. |
| Te-form | 鈍くて nibukute | — | Links to the next clause: “~ and …”. |
| Adverb | 鈍く nibuku | — | Turns it into “~ly”, describing a verb. |
| Before a noun | 鈍い〜 nibui〜 | — | How it attaches when it modifies a noun. |
| Conditional (~ば/なら) | 鈍ければ nibukereba | — | “if it is ~”. |
| Conditional (~たら) | 鈍かったら nibukattara | — | “if / when it is ~”. The everyday conditional. |
| Become (~なる) | 鈍くなる nibukunaru | 鈍くなります nibukunarimasu | “becomes ~” — the change-of-state form. |
| Too much (~すぎる) | 鈍すぎる nibusugiru | 鈍すぎます nibusugimasu | “too ~”. |
| Looks ~ (~そう) | 鈍そう nibusou | 鈍そうです nibusoudesu | “looks / seems ~” from appearance. |
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Why it conjugates this way
I-adjectives carry their own tense: drop the final い and the endings attach straight to the stem. No だ, no です needed to make a complete sentence.
See the full rules in the adjective conjugation guide.