大切 (taisetsu) conjugation
important
大切 (たいせつ, taisetsu) 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 | 大切だ taisetsuda | 大切です taisetsudesu | The form you look up. Also the casual “is ~”. |
| Negative | 大切じゃない taisetsujanai | 大切じゃないです taisetsujanaidesu | “is not ~”. |
| Past | 大切だった taisetsudatta | 大切でした taisetsudeshita | “was ~”. |
| Past negative | 大切じゃなかった taisetsujanakatta | 大切じゃなかったです taisetsujanakattadesu | “was not ~”. |
| Te-form | 大切で taisetsude | — | Links to the next clause: “~ and …”. |
| Adverb | 大切に taisetsuni | — | Turns it into “~ly”, describing a verb. |
| Before a noun | 大切な〜 taisetsuna〜 | — | How it attaches when it modifies a noun. |
| Conditional (~ば/なら) | 大切なら taisetsunara | — | “if it is ~”. |
| Conditional (~たら) | 大切だったら taisetsudattara | — | “if / when it is ~”. The everyday conditional. |
| Become (~なる) | 大切になる taisetsuninaru | 大切になります taisetsuninarimasu | “becomes ~” — the change-of-state form. |
| Too much (~すぎる) | 大切すぎる taisetsusugiru | 大切すぎます taisetsusugimasu | “too ~”. |
| Looks ~ (~そう) | 大切そう taisetsusou | 大切そうです taisetsusoudesu | “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.