Preterite and Imperfect: When a Non-Target Form Is Not an Error
In a Grade 10 Spanish class in Guyana, students wrote a short narrative about a visit to a market. The teacher displays five underlined verb forms from one paragraph: 'Ayer, mientras (1) caminaba por el mercado, (2) vi a una señora que (3) vendía mangos. Le compré dos. Cuando (4) llegué a casa, mi hermana (5) miraba la televisión.' The student's original choices were: (1) caminaba, (2) vi, (3) vendía, (4) llegué, (5) miró. During feedback, one student asks why (5) cannot be 'miró' if the sister finished watching. Another asks why (3) is not 'vendió' because the purchase happened. The teacher wants to avoid telling students that imperfect equals description and preterite equals action, because the class then over-applies the rule. The teacher must decide which forms are genuinely errors, which are acceptable alternatives with meaning shifts, and how to explain the contrast with a concrete test.
1. For each numbered form, state whether the student's version is acceptable, and explain the meaning difference where both tenses are possible.
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(1) 'caminaba' is acceptable: it sets the background scene for the encounter. (2) 'vi' is acceptable: it reports a completed event that moves the narrative forward. (3) 'vendía' is acceptable and probably preferable: it describes the woman's ongoing activity or the scene at the stall; 'vendió' would shift attention to a completed sale, which is possible but changes the focus. (4) 'llegué' is acceptable: it marks the boundary event. (5) 'miró' is acceptable, and so is 'miraba'. With 'miró', the sister's action is presented as a completed event that the arrival interrupted or followed; with 'miraba', it is presented as the background activity in progress when the narrator arrived. The key judgement is that (5) is not an error simply because the teacher expected imperfect. Both forms are grammatical; the choice depends on whether the writer wants to frame the action as an event or as a scene. This is precisely the over-application the teacher wants to avoid.
2. Identify one likely systematic error in the class set and propose a teaching rule that avoids the oversimplification.
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A likely systematic error is treating every completed action as preterite and every description as imperfect, then correcting any departure from that pattern. That rule cannot explain (3) or (5), where both tenses are possible with different viewpoints. A better teaching rule is: choose the tense according to how the writer frames the action, not according to a fixed label. Ask two questions: 'Is this presented as a bounded event on the timeline, or as the open frame/background?' and 'Does an adverbial or another clause interrupt it?' For example, 'cuando llegué' provides a boundary; the sister's watching can be framed as background ('miraba') or as a separate event ('miró'). The teacher should present contrastive pairs and ask students to explain the change in focus, rather than asking them to memorise 'description versus action'.
3. Design a 5-minute oral contrast activity using the market paragraph.
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Show the sentence 'Cuando llegué a casa, mi hermana miraba la televisión' and ask pairs to change 'miraba' to 'miró'. Give them 90 seconds to decide what changes: with 'miraba', the watching is already in progress and forms the background; with 'miró', the watching is a completed event that may follow the arrival. Then ask two pairs to explain in Spanish, using prompts such as 'Antes / En ese momento / Después'. Next, do the same with 'vendía' and 'vendió': ask whether the woman is described at her stall or whether a specific sale is reported. Close by asking students to state a rule in their own words, not to repeat the teacher's wording. The activity is short because the aim is to make the contrast audible and debatable, not to cover every use of the imperfect.