沸く (waku) conjugation
to boil, to grow hot
沸く (わく, waku) 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 | 沸く waku | 沸きます wakimasu | The form you look up. Also the casual present and future. |
| Plain negative | 沸かない wakanai | 沸きません wakimasen | “doesn’t / won’t”. From here it conjugates like an i-adjective. |
| Plain past | 沸いた waita | 沸きました wakimashita | The casual past — same ending as the te-form, with た/だ. |
| Plain past negative | 沸かなかった wakanakatta | 沸きませんでした wakimasendeshita | “didn’t”. The negative past, still i-adjective-shaped. |
| Te-form | 沸いて waite | — | The connector: requests, linking clauses, ~ている. |
| Progressive (~ている) | 沸いている waiteiru | 沸いています waiteimasu | “is ~ing”, or an ongoing resulting state. |
| Desire (~たい) | 沸きたい wakitai | 沸きたいです wakitaidesu | “want to ~”. Behaves as an i-adjective. |
| Volitional | 沸こう wakou | 沸きましょう wakimashou | “let’s ~” / “I think I’ll ~”. |
| Potential | 沸ける wakeru | 沸けます wakemasu | “can ~”. What you could do; the object often takes が. |
| Passive | 沸かれる wakareru | 沸かれます wakaremasu | “is ~ed”. Also the honorific and the suffering passive. |
| Causative | 沸かせる wakaseru | 沸かせます wakasemasu | Make or let someone do it. |
| Causative-passive | 沸かされる wakasareru | 沸かされます wakasaremasu | Be made to do it — the long one. |
| Imperative | 沸け wake | 沸いてください waitekudasai | Blunt order. Use ~てください in real life. |
| Prohibitive | 沸くな wakuna | — | “don’t!” — dictionary form + な. |
| Conditional (~ば) | 沸けば wakeba | — | “if ~”. General rules and hypotheticals. |
| Conditional (~たら) | 沸いたら waitara | — | “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.