真剣 (shinken) conjugation
seriousness, earnestness
真剣 (しんけん, shinken) 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 | 真剣だ shinkenda | 真剣です shinkendesu | The form you look up. Also the casual “is ~”. |
| Negative | 真剣じゃない shinkenjanai | 真剣じゃないです shinkenjanaidesu | “is not ~”. |
| Past | 真剣だった shinkendatta | 真剣でした shinkendeshita | “was ~”. |
| Past negative | 真剣じゃなかった shinkenjanakatta | 真剣じゃなかったです shinkenjanakattadesu | “was not ~”. |
| Te-form | 真剣で shinkende | — | Links to the next clause: “~ and …”. |
| Adverb | 真剣に shinkenni | — | Turns it into “~ly”, describing a verb. |
| Before a noun | 真剣な〜 shinkenna〜 | — | How it attaches when it modifies a noun. |
| Conditional (~ば/なら) | 真剣なら shinkennara | — | “if it is ~”. |
| Conditional (~たら) | 真剣だったら shinkendattara | — | “if / when it is ~”. The everyday conditional. |
| Become (~なる) | 真剣になる shinkenninaru | 真剣になります shinkenninarimasu | “becomes ~” — the change-of-state form. |
| Too much (~すぎる) | 真剣すぎる shinkensugiru | 真剣すぎます shinkensugimasu | “too ~”. |
| Looks ~ (~そう) | 真剣そう shinkensou | 真剣そうです shinkensoudesu | “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.