〜ことだ

koto da

should; the best thing is to (advice)

Formation

Verb-dict / Verb-nai + ことだ

Chinese meanings

应该；最好

Chinese formation

动词辞书形／ない形＋ことだ

Chinese usage

针对某个目标或情况给出建议。

Chinese notes

常用于有资格给建议的人对晚辈等说，不宜用于上司。

Examples

Furigana

日本語にほんごが上じょう手ずになりたいなら、毎まい日にち少すこしずつでも話はなすことだ。
If you want to get good at Japanese, you should speak it every day, even just a little.
如果想提高日语，应该每天说一点。
風邪かぜを早はやく治なおしたければ、無む理りをしないでゆっくり休やすむことです。
If you want to get over your cold quickly, the best thing is not to push yourself and to rest well.
如果想早点治好感冒，最好不要勉强，好好休息。
人ひとの話はなしは最さい後ごまでよく聞きくことだ。
You should always listen carefully to what people say, right to the end.
应该认真听完别人说的话。

Notes

Personal advice from someone in a position to give it (teacher, parent, senior). Not used toward superiors. Compare 〜ものだ, which appeals to general norms.

#advice

Related N3 grammar

〜ものだ〜ものではない〜ことはない〜ばいい〜べきだ / 〜べきではない

Suggest an improvement

Use this entry in code

import { getGrammarById } from 'kotowa';
getGrammarById('koto-da');

{
  "id": "koto-da",
  "pattern": "〜ことだ",
  "romaji": "koto da",
  "level": "N3",
  "meaning": "should; the best thing is to (advice)",
  "formation": "Verb-dict / Verb-nai + ことだ",
  "examples": [
    {
      "ja": "日本語が上手になりたいなら、毎日少しずつでも話すことだ。",
      "furigana": "{日本語|にほんご}が{上手|じょうず}になりたいなら、{毎日|まいにち}{少|すこ}しずつでも{話|はな}すことだ。",
      "en": "If you want to get good at Japanese, you should speak it every day, even just a little."
    },
    {
      "ja": "風邪を早く治したければ、無理をしないでゆっくり休むことです。",
      "furigana": "{風邪|かぜ}を{早|はや}く{治|なお}したければ、{無理|むり}をしないでゆっくり{休|やす}むことです。",
      "en": "If you want to get over your cold quickly, the best thing is not to push yourself and to rest well."
    },
    {
      "ja": "人の話は最後までよく聞くことだ。",
      "furigana": "{人|ひと}の{話|はなし}は{最後|さいご}までよく{聞|き}くことだ。",
      "en": "You should always listen carefully to what people say, right to the end."
    }
  ],
  "tags": [
    "advice"
  ],
  "notes": "Personal advice from someone in a position to give it (teacher, parent, senior). Not used toward superiors. Compare 〜ものだ, which appeals to general norms.",
  "zh": {
    "status": "reviewed",
    "source_hash": "e1cf90d5c10676f00ad6385c3deda1b5b845587be09c93c8892359963ed1dd43",
    "meanings": [
      "应该",
      "最好"
    ],
    "formation": "动词辞书形／ない形＋ことだ",
    "explanation": "针对某个目标或情况给出建议。",
    "notes": "常用于有资格给建议的人对晚辈等说，不宜用于上司。",
    "examples": [
      {
        "ja": "日本語が上手になりたいなら、毎日少しずつでも話すことだ。",
        "zh": "如果想提高日语，应该每天说一点。"
      },
      {
        "ja": "風邪を早く治したければ、無理をしないでゆっくり休むことです。",
        "zh": "如果想早点治好感冒，最好不要勉强，好好休息。"
      },
      {
        "ja": "人の話は最後までよく聞くことだ。",
        "zh": "应该认真听完别人说的话。"
      }
    ],
    "references": [
      "sources/grammar/n3.json#koto-da",
      "Original Chinese authored and reviewed by Codex; no independent human review"
    ],
    "reviewer": "Codex",
    "review_method": "ai",
    "reviewed_at": "2026-10-28",
    "review_hash": "7499deb12a564830685eee7a807c532f419312602f8d0db8181f21a7f6290ebe"
  }
}