陽気 (youki) conjugation
season, weather, cheerfulness
陽気 (ようき, youki) is a na-adjective. Na-adjectives behave like nouns. The word itself never changes — you conjugate だ/です after it, and you need な to put it in front of a noun.
Conjugation table
| Form | Plain (casual) | Polite (~です) | When you use it |
|---|---|---|---|
| Dictionary / plain | 陽気だ youkida | 陽気です youkidesu | The form you look up. Also the casual “is ~”. |
| Negative | 陽気じゃない youkijanai | 陽気じゃないです youkijanaidesu | “is not ~”. |
| Past | 陽気だった youkidatta | 陽気でした youkideshita | “was ~”. |
| Past negative | 陽気じゃなかった youkijanakatta | 陽気じゃなかったです youkijanakattadesu | “was not ~”. |
| Te-form | 陽気で youkide | — | Links to the next clause: “~ and …”. |
| Adverb | 陽気に youkini | — | Turns it into “~ly”, describing a verb. |
| Before a noun | 陽気な〜 youkina〜 | — | How it attaches when it modifies a noun. |
| Conditional (~ば/なら) | 陽気なら youkinara | — | “if it is ~”. |
| Conditional (~たら) | 陽気だったら youkidattara | — | “if / when it is ~”. The everyday conditional. |
| Become (~なる) | 陽気になる youkininaru | 陽気になります youkininarimasu | “becomes ~” — the change-of-state form. |
| Too much (~すぎる) | 陽気すぎる youkisugiru | 陽気すぎます youkisugimasu | “too ~”. |
| Looks ~ (~そう) | 陽気そう youkisou | 陽気そうです youkisoudesu | “looks / seems ~” from appearance. |
🔊 Tap any Japanese word to hear it spoken.
Why it conjugates this way
Na-adjectives behave like nouns. The word itself never changes — you conjugate だ/です after it, and you need な to put it in front of a noun.
See the full rules in the adjective conjugation guide.