〜だ

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

{
  "id": "da",
  "pattern": "〜だ",
  "romaji": "da",
  "level": "N5",
  "meaning": "is; am; are (plain copula)",
  "formation": "Noun + だ / na-Adj + だ",
  "examples": [
    {
      "ja": "今日は日曜日だ。",
      "furigana": "{今日|きょう}は{日曜日|にちようび}だ。",
      "en": "Today is Sunday."
    },
    {
      "ja": "あの人は私の兄だ。",
      "furigana": "あの{人|ひと}は{私|わたし}の{兄|あに}だ。",
      "en": "That person is my older brother."
    },
    {
      "ja": "明日は休みだから、ゆっくり寝る。",
      "furigana": "{明日|あした}は{休|やす}みだから、ゆっくり{寝|ね}る。",
      "en": "Tomorrow is a day off, so I'll sleep in."
    }
  ],
  "tags": [
    "copula",
    "casual"
  ],
  "notes": "Forms: だ, じゃない, だった, じゃなかった. Never used right after an い-adjective (高いだ is wrong). Often dropped in casual questions: 学生？",
  "zh": {
    "status": "reviewed",
    "source_hash": "4036ce085cdeee76e3ba6c6c7f8d8d6b15537b4fe3b5a9f5638e9337fe22af6e",
    "meanings": [
      "是",
      "简体判断"
    ],
    "formation": "名词／な形容词＋だ",
    "explanation": "以简体表达判断或状态。",
    "notes": "い形容词后不能直接接だ；过去形式为だった。",
    "examples": [
      {
        "ja": "今日は日曜日だ。",
        "zh": "今天是星期日。"
      },
      {
        "ja": "あの人は私の兄だ。",
        "zh": "那个人是我哥哥。"
      },
      {
        "ja": "明日は休みだから、ゆっくり寝る。",
        "zh": "明天休息，所以我要睡个懒觉。"
      }
    ],
    "references": [
      "sources/grammar/n5.json#da",
      "Original Chinese authored and reviewed by Codex; no independent human review"
    ],
    "reviewer": "Codex",
    "review_method": "ai",
    "reviewed_at": "2026-10-28",
    "review_hash": "57f42bf5d12c8954ca657dadbb09219d9bd7047c58c39c91903b94b7f1419420"
  }
}