Case government and an aspect warning
A writing group reviews three original Russian examples: «Я интересуюсь о русской литературе», «Не открывай окно!» and «Осторожно, не упади!». The task asks for a correction where one is needed and an explanation of why the two negative imperatives need not use the same aspect. One learner adds more prepositions to the first sentence because the German equivalent contains a preposition. Another declares the final warning impossible because a memorized rule says all negative imperatives are imperfective. A third notices that prohibition and warning can present the unwanted action differently. The exercise gives no actual safety procedure or medical situation; the examples are linguistic material. Answers must identify the governing construction and the communicative intention rather than treating a translation mnemonic as a universal grammatical law.
1. Correct the first sentence and explain the case.
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Я интересуюсь русской литературой. Интересоваться governs instrumental without the preposition о. The noun and adjective must be inflected together; adding a German-inspired preposition does not preserve the Russian construction.
2. Explain the two imperatives without inventing an absolute rule.
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Не открывай uses imperfective in a prohibition. Не упади uses perfective in a warning against an unwanted occurrence. These examples show why a common imperfective pattern cannot be generalized to every negative imperative regardless of meaning.