{
  "chapter_id": "31",
  "slug": "imperfect-tense",
  "title": "Imperfect Tense",
  "time_range_sec": [8311, 8722],
  "summary": "The imperfect describes habitual or ongoing actions in the past ('used to' / 'was -ing'); it has just two regular ending sets (-ar vs -er/-ir) and only three irregulars: ser, ir, ver.",
  "suggested_grammar_note_id": "preterite-vs-imperfect",
  "rules": [
    {"title": "When to use", "bullets": ["Habits in the past ('I used to...').", "Background or ongoing past action ('was/were -ing').", "Descriptions: age, time, weather, traits, mental/emotional states."]},
    {"title": "Endings", "bullets": ["-ar verbs: -aba, -abas, -aba, -ábamos, -abais, -aban.", "-er and -ir verbs share: -ía, -ías, -ía, -íamos, -íais, -ían."]},
    {"title": "Irregulars", "bullets": ["Only three: ser → era, ir → iba, ver → veía.", "No stem changes anywhere else."]},
    {"title": "Past progressive", "bullets": ["Use estar in the imperfect + gerund: yo estaba hablando.", "Never use the preterite of estar for ongoing background action."]},
    {"title": "Vs preterite", "bullets": ["Preterite = a single completed event ('I went, I ate').", "Imperfect = habit / background / description ('I used to go, I was eating')."]}
  ],
  "examples": [
    {"es": "Yo hablaba español de niño.", "en": "I used to speak Spanish as a kid.", "tags": ["habit"]},
    {"es": "Tú caminabas cada día.", "en": "You used to walk every day.", "tags": ["habit"]},
    {"es": "Él comía por las mañanas.", "en": "He used to eat in the mornings.", "tags": ["habit"]},
    {"es": "Nosotros vivíamos en Madrid.", "en": "We used to live in Madrid.", "tags": ["habit"]},
    {"es": "Yo iba a la escuela todos los días.", "en": "I used to go to school every day.", "tags": ["irregular"]},
    {"es": "Yo era estudiante.", "en": "I used to be a student.", "tags": ["ser", "trait"]},
    {"es": "Él era rápido.", "en": "He used to be fast.", "tags": ["ser", "trait"]},
    {"es": "Yo veía la televisión.", "en": "I used to watch TV.", "tags": ["ver"]},
    {"es": "Yo estaba hablando con María.", "en": "I was speaking with María.", "tags": ["progressive"]},
    {"es": "Tú estabas muy feliz.", "en": "You were very happy.", "tags": ["estar"]},
    {"es": "Eran las tres de la tarde.", "en": "It was 3 in the afternoon.", "tags": ["time"]},
    {"es": "Hacía frío y llovía.", "en": "It was cold and raining.", "tags": ["weather"]}
  ],
  "vocab": [
    {"es": "siempre", "en": "always", "pos": "adv"},
    {"es": "cada día", "en": "every day", "pos": "phrase"},
    {"es": "todos los días", "en": "every day", "pos": "phrase"},
    {"es": "a menudo", "en": "often", "pos": "adv"},
    {"es": "mientras", "en": "while", "pos": "adv"},
    {"es": "de niño/a", "en": "as a child", "pos": "phrase"}
  ],
  "conjugation_tables": [
    {
      "verb": "hablar",
      "tense_id": "ind_imperfecto",
      "forms": {"yo": "hablaba", "tu": "hablabas", "el": "hablaba", "nosotros": "hablábamos", "vosotros": "hablabais", "ellos": "hablaban"}
    },
    {
      "verb": "comer",
      "tense_id": "ind_imperfecto",
      "forms": {"yo": "comía", "tu": "comías", "el": "comía", "nosotros": "comíamos", "vosotros": "comíais", "ellos": "comían"}
    },
    {
      "verb": "vivir",
      "tense_id": "ind_imperfecto",
      "forms": {"yo": "vivía", "tu": "vivías", "el": "vivía", "nosotros": "vivíamos", "vosotros": "vivíais", "ellos": "vivían"}
    },
    {
      "verb": "ser",
      "tense_id": "ind_imperfecto",
      "forms": {"yo": "era", "tu": "eras", "el": "era", "nosotros": "éramos", "vosotros": "erais", "ellos": "eran"}
    },
    {
      "verb": "ir",
      "tense_id": "ind_imperfecto",
      "forms": {"yo": "iba", "tu": "ibas", "el": "iba", "nosotros": "íbamos", "vosotros": "ibais", "ellos": "iban"}
    },
    {
      "verb": "ver",
      "tense_id": "ind_imperfecto",
      "forms": {"yo": "veía", "tu": "veías", "el": "veía", "nosotros": "veíamos", "vosotros": "veíais", "ellos": "veían"}
    }
  ],
  "exercises": [
    {"sentence": "Cuando era niño, _____ al parque todos los días.", "correct": "iba", "distractor": "fui", "explanation": "Habitual past action → imperfect of ir."},
    {"sentence": "Mientras yo _____, sonó el teléfono.", "correct": "comía", "distractor": "comí", "explanation": "Background ongoing action → imperfect."},
    {"sentence": "Cuando éramos jóvenes, nosotros _____ en Madrid.", "correct": "vivíamos", "distractor": "vivimos", "explanation": "Habitual past → imperfect of vivir."},
    {"sentence": "_____ las cinco cuando llegó.", "correct": "Eran", "distractor": "Fueron", "explanation": "Time in the past always uses imperfect of ser."},
    {"sentence": "Mi abuela _____ mucho la tele.", "correct": "veía", "distractor": "vio", "explanation": "Habit → imperfect of ver."},
    {"sentence": "Yo _____ hablando cuando entró.", "correct": "estaba", "distractor": "estuve", "explanation": "Past progressive needs estar in the imperfect."},
    {"sentence": "Él _____ muy alto de joven.", "correct": "era", "distractor": "fue", "explanation": "Trait/description → imperfect of ser."},
    {"sentence": "Tú siempre _____ pan en la panadería.", "correct": "comprabas", "distractor": "compraste", "explanation": "'Siempre' + habitual action → imperfect."}
  ],
  "caveats": "OCR mangled accents and verb stems heavily; rebuilt all paradigms from standard imperfect rules."
}