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Questions & Answers about Прошлый период был сложным.
What case, number, and gender are прошлый период, and why are they in the nominative?
прошлый (adjective) agrees with период (noun) in gender (masculine), number (singular), and case (nominative). They form the subject of the sentence, so both must appear in the nominative singular masculine.
Why is сложным in the instrumental case rather than the nominative?
In Russian, with a past‐tense form of быть (here был), the predicate adjective takes the instrumental case. That’s why you say был сложным, not был сложный.
Could we omit был and just say Прошлый период сложным?
In standard Russian you need the linking verb быть in the past or future tense to form a complete clause. Native speakers might drop был in telegram style or headings—for example, on a slide title you could write Прошлый период. Сложным—but in normal speech or writing you include был сложным.
Can we use a short‐form adjective and say Прошлый период сложен instead?
Yes. The short form сложен (masculine singular) is grammatically correct and means essentially the same. It feels more formal or literary. In everyday narrative you’ll more often hear the full form with был сложным.
What’s the difference between прошлый период and прошедший период?
• прошлый focuses on sequence: “the previous/last period.”
• прошедший emphasizes completion: “the period that has passed.”
In many contexts they overlap, but прошлый период is more neutral and common for “last period.”
Could we replace сложным with трудным? What’s the nuance?
• сложный highlights complexity or many interconnected parts.
• трудный stresses difficulty or hardship in doing something.
You can say Прошлый период был трудным if you mean “it was hard/taxing.” Both adjectives would be in the instrumental after был.
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