{
  "chapter_id": "26",
  "slug": "past-tense-of-ser-and-ir",
  "title": "Past Tense of Ser and Ir",
  "time_range_sec": [6488, 6872],
  "summary": "Ser and ir share identical preterite conjugations: fui, fuiste, fue, fuimos, fuisteis, fueron. Context, especially the preposition 'a', distinguishes them. No accents on these forms.",
  "suggested_grammar_note_id": "preterite-vs-imperfect",
  "rules": [
    {"title": "Identical forms", "bullets": ["ser and ir share the exact same preterite: fui, fuiste, fue, fuimos, fuisteis, fueron.", "No written accents on any form."]},
    {"title": "Distinguishing ser from ir", "bullets": ["If the preposition 'a' follows (with or without an infinitive), the verb is ir.", "Otherwise, the verb is usually ser."]},
    {"title": "When ser is used in preterite", "bullets": ["Events that took place at a specific moment (when, where, how).", "Completed states/judgments about events: 'La película fue aburrida.'", "For describing how things were generally, use the imperfect (era), not preterite."]}
  ],
  "examples": [
    {"es": "Yo fui a la tienda.", "en": "I went to the store.", "tags": ["ir", "preterite"]},
    {"es": "Tú fuiste a hacer tu tarea.", "en": "You went to do your homework.", "tags": ["ir", "preterite"]},
    {"es": "Ella fue al concierto ayer.", "en": "She went to the concert yesterday.", "tags": ["ir", "preterite"]},
    {"es": "Fuimos a ver la fiesta.", "en": "We went to see the party.", "tags": ["ir", "preterite"]},
    {"es": "Ellos fueron a la playa.", "en": "They went to the beach.", "tags": ["ir", "preterite"]},
    {"es": "La película fue aburrida.", "en": "The movie was boring.", "tags": ["ser", "preterite", "event"]},
    {"es": "Fue difícil hacer la prueba.", "en": "It was difficult to do the test.", "tags": ["ser", "preterite"]},
    {"es": "La fiesta fue en el club.", "en": "The party was in the club.", "tags": ["ser", "preterite", "event-location"]},
    {"es": "Fue un día largo.", "en": "It was a long day.", "tags": ["ser", "preterite"]},
    {"es": "Fuimos amigos por años.", "en": "We were friends for years.", "tags": ["ser", "preterite"]}
  ],
  "vocab": [
    {"es": "ser", "en": "to be", "pos": "verb"},
    {"es": "ir", "en": "to go", "pos": "verb"},
    {"es": "la película", "en": "the movie", "pos": "noun"},
    {"es": "la prueba", "en": "the test", "pos": "noun"},
    {"es": "el concierto", "en": "the concert", "pos": "noun"},
    {"es": "la fiesta", "en": "the party", "pos": "noun"}
  ],
  "conjugation_tables": [
    {
      "verb": "ser",
      "tense_id": "ind_preterito",
      "forms": {"yo":"fui","tu":"fuiste","el":"fue","nosotros":"fuimos","vosotros":"fuisteis","ellos":"fueron"}
    },
    {
      "verb": "ir",
      "tense_id": "ind_preterito",
      "forms": {"yo":"fui","tu":"fuiste","el":"fue","nosotros":"fuimos","vosotros":"fuisteis","ellos":"fueron"}
    }
  ],
  "exercises": [
    {"sentence": "Ayer yo _____ al cine.", "correct": "fui", "distractor": "iba", "explanation": "Preterite of ir = fui (completed action). 'Iba' is imperfect."},
    {"sentence": "La fiesta _____ muy divertida.", "correct": "fue", "distractor": "era", "explanation": "An event that happened — use the preterite of ser (fue)."},
    {"sentence": "Nosotros _____ a la playa el sábado.", "correct": "fuimos", "distractor": "vamos", "explanation": "Preterite of ir = fuimos. 'Vamos' is present."},
    {"sentence": "Tú _____ doctor antes, ¿verdad?", "correct": "fuiste", "distractor": "fue", "explanation": "Tú preterite of ser = fuiste."},
    {"sentence": "Ellos _____ al supermercado anoche.", "correct": "fueron", "distractor": "fueran", "explanation": "Preterite of ir, ellos form = fueron."},
    {"sentence": "_____ difícil aprender español.", "correct": "Fue", "distractor": "Era", "explanation": "Completed evaluation of an event — preterite of ser (fue)."},
    {"sentence": "¿A dónde _____ tú anoche?", "correct": "fuiste", "distractor": "fueras", "explanation": "Preterite of ir, tú form = fuiste."}
  ],
  "caveats": "OCR rendered 'fui' as 'F', 'fue' as 'Fu', 'fueron' as 'fuon' — reconstructed standard preterite forms."
}