鈍る (niburu) conjugation
to become less capable, to grow dull, to become blunt, to weaken
鈍る (にぶる, niburu) is a godan verb. Godan verbs change their final kana up and down its column of the kana chart — the a-row for negatives, the i-row before ます, the e-row for potential and ば. Every form below is tappable — hear it, then say it back.
Conjugation table
| Form | Plain (casual) | Polite (~ます) | When you use it |
|---|---|---|---|
| Dictionary / plain | 鈍る niburu | 鈍ります niburimasu | The form you look up. Also the casual present and future. |
| Plain negative | 鈍らない niburanai | 鈍りません niburimasen | “doesn’t / won’t”. From here it conjugates like an i-adjective. |
| Plain past | 鈍った nibutta | 鈍りました niburimashita | The casual past — same ending as the te-form, with た/だ. |
| Plain past negative | 鈍らなかった niburanakatta | 鈍りませんでした niburimasendeshita | “didn’t”. The negative past, still i-adjective-shaped. |
| Te-form | 鈍って nibutte | — | The connector: requests, linking clauses, ~ている. |
| Progressive (~ている) | 鈍っている nibutteiru | 鈍っています nibutteimasu | “is ~ing”, or an ongoing resulting state. |
| Desire (~たい) | 鈍りたい niburitai | 鈍りたいです niburitaidesu | “want to ~”. Behaves as an i-adjective. |
| Volitional | 鈍ろう niburou | 鈍りましょう niburimashou | “let’s ~” / “I think I’ll ~”. |
| Potential | 鈍れる nibureru | 鈍れます niburemasu | “can ~”. What you could do; the object often takes が. |
| Passive | 鈍られる niburareru | 鈍られます niburaremasu | “is ~ed”. Also the honorific and the suffering passive. |
| Causative | 鈍らせる niburaseru | 鈍らせます niburasemasu | Make or let someone do it. |
| Causative-passive | 鈍らされる niburasareru | 鈍らされます niburasaremasu | Be made to do it — the long one. |
| Imperative | 鈍れ nibure | 鈍ってください nibuttekudasai | Blunt order. Use ~てください in real life. |
| Prohibitive | 鈍るな niburuna | — | “don’t!” — dictionary form + な. |
| Conditional (~ば) | 鈍れば nibureba | — | “if ~”. General rules and hypotheticals. |
| Conditional (~たら) | 鈍ったら nibuttara | — | “if / when ~”. The everyday conditional. |
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Why it conjugates this way
Godan verbs change their final kana up and down its column of the kana chart — the a-row for negatives, the i-row before ます, the e-row for potential and ば.
See the full rules on the verb conjugation guide.