なくす (nakusu) conjugation
to lose something
なくす (なくす, nakusu) 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.
Written 無くす in kanji, but usually written in kana alone.
Conjugation table
| Form | Plain (casual) | Polite (~ます) | When you use it |
|---|---|---|---|
| Dictionary / plain | なくす nakusu | なくします nakushimasu | The form you look up. Also the casual present and future. |
| Plain negative | なくさない nakusanai | なくしません nakushimasen | “doesn’t / won’t”. From here it conjugates like an i-adjective. |
| Plain past | なくした nakushita | なくしました nakushimashita | The casual past — same ending as the te-form, with た/だ. |
| Plain past negative | なくさなかった nakusanakatta | なくしませんでした nakushimasendeshita | “didn’t”. The negative past, still i-adjective-shaped. |
| Te-form | なくして nakushite | — | The connector: requests, linking clauses, ~ている. |
| Progressive (~ている) | なくしている nakushiteiru | なくしています nakushiteimasu | “is ~ing”, or an ongoing resulting state. |
| Desire (~たい) | なくしたい nakushitai | なくしたいです nakushitaidesu | “want to ~”. Behaves as an i-adjective. |
| Volitional | なくそう nakusou | なくしましょう nakushimashou | “let’s ~” / “I think I’ll ~”. |
| Potential | なくせる nakuseru | なくせます nakusemasu | “can ~”. What you could do; the object often takes が. |
| Passive | なくされる nakusareru | なくされます nakusaremasu | “is ~ed”. Also the honorific and the suffering passive. |
| Causative | なくさせる nakusaseru | なくさせます nakusasemasu | Make or let someone do it. |
| Causative-passive | なくさせられる nakusaserareru | なくさせられます nakusaseraremasu | Be made to do it — the long one. |
| Imperative | なくせ nakuse | なくしてください nakushitekudasai | Blunt order. Use ~てください in real life. |
| Prohibitive | なくすな nakusuna | — | “don’t!” — dictionary form + な. |
| Conditional (~ば) | なくせば nakuseba | — | “if ~”. General rules and hypotheticals. |
| Conditional (~たら) | なくしたら nakushitara | — | “if / when ~”. The everyday conditional. |
🔊 Tap any Japanese word to hear it spoken.
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.