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Questions & Answers about Обе сестры купили торт.
What does Обе mean and why is it used here?
Обе means both. Russian distinguishes gender for this word: оба is used with masculine or neuter nouns, while обе is used with feminine nouns. Since сёстры (sisters) is feminine plural, we use обе to agree in gender and number.
Why Обе, not Оба?
Оба is the masculine/neuter form (e.g. оба брата – both brothers, оба окна – both windows). For feminine nouns like сёстры, you must use обе (e.g. обе сестры – both sisters).
What case is сестры, and why is it in the nominative plural?
Сёстры here is in the nominative plural because it’s the grammatical subject of the sentence. In Russian, subjects appear in the nominative case. The singular сестра́ becomes сёстры́ in the nominative plural.
Why is the verb купили in the past tense plural? Why isn’t it купила?
Russian past-tense verbs agree with the subject’s number (and, in singular, with its gender). Since обе сестры is plural, we use купи́ли, the one past-tense plural form for купить. If it were one sister, you’d say купи́ла (feminine singular).
Why is купили perfective rather than imperfective like покупали?
Russian verbs have two aspects. Купи́ли (perfective) indicates a completed action—“they bought [and finished buying] the cake.” Покупа́ли (imperfective) would suggest an ongoing or habitual action (“they were buying cakes” or “they used to buy cakes regularly”), not a single completed purchase.
What case is торт, and how do you know it’s unchanged?
Торт is in the accusative singular as the direct object of купили. For inanimate masculine nouns, the accusative form is identical to the nominative, so торт looks the same. It follows the verb and answers “what did they buy?” confirming its role as the object.
Why are there no words for “a” or “the” before торт?
Russian has no articles. You don’t use words like a or the. Definiteness or indefiniteness is understood from context. Thus торт can mean either a cake or the cake, depending on the situation.
Why is сестры written with е but pronounced сё́стры (with ё)?
In standard Russian spelling, the letter ё is often printed without its two dots, appearing as е. However, you still pronounce it as ё and put the stress on that syllable. So сестры is written like that but always pronounced сё́стры.
Could you say две сестры купили торт instead of обе сестры купили торт, and is there a nuance?
Yes. Две сестры купили торт literally means two sisters bought a cake—it simply states the number. Обе emphasizes that you’re talking about both sisters in a known pair. Use две when counting out of many, обе when you refer to an entire group of two.
If each sister bought her own cake, how would you express that?
You could say Обе сестры купили по торту, literally “both sisters bought a cake each.” To be extra clear you might add по одному торту:
• Обе сестры купили по одному торту.
Can the word order change, and does it affect emphasis?
Yes. Thanks to case endings, Russian word order is flexible. The neutral order is Subject-Verb-Object:
• Обе сестры купили торт.
To shift focus you can move parts:
• Купили обе сестры торт – emphasizes the action of buying.
• Торт купили обе сестры – emphasizes the cake (e.g. as opposed to something else).
The core meaning stays the same; only the emphasis changes.