Learn Hardcore Russian: Моя компания купила новое оборудование.

In Russian past-tense verbs agree with the subject’s gender and number. Компания is a feminine noun, so the past tense of купить takes the feminine ending -ла, giving купила. If the subject were masculine (e.g. директор), it would be купил.

Why does новое end in -ое, and how does it agree with оборудование?

Новое is the neuter singular form of the adjective новый in the nominative/accusative case. It must match оборудование, which is a neuter singular noun ending in -ие. In Russian adjectives always agree with their nouns in gender (masculine/feminine/neuter), number (singular/plural), and case.

Which case is оборудование in, and why doesn’t its ending change?

Here оборудование is the direct object of the verb, so it’s in the accusative case. Neuter inanimate nouns have identical forms in nominative and accusative, so you don’t see a change in the ending.

Why aren’t there words for “the” or “a” before компания or оборудование in Russian?

Russian has no articles (no direct equivalents of “a,” “an,” or “the”). Definiteness or indefiniteness is understood from context. So “a company” or “the company” is just компания.

Why does the sentence use купила (perfective) and not покупала (imperfective)?

Russian verbs have two aspects:

Perfective (e.g. купить) indicates a completed action (“has bought,” one-time event).
Imperfective (e.g. покупать) indicates an ongoing, habitual, or repeated action (“was buying,” “used to buy”).
Since the company completed the purchase, you use the perfective купила.

Why is моя used instead of мой before компания?

Possessive pronouns in Russian agree with the noun in gender, number, and case. Моя is the feminine singular nominative form of “my,” matching the feminine noun компания.

Could I say наша компания instead of моя компания? When do you use one over the other?

Yes.

Наша компания (“our company”) is used when you speak on behalf of a group (e.g. employees, team).
Моя компания (“my company”) is used when you refer to ownership or founding—speaking personally about your own business.

Why is оборудование singular even though “equipment” in English is uncountable?

Оборудование is a collective, mass (uncountable) noun in Russian and only exists in the singular. To count individual items you add a classifier, e.g. одна штука оборудования, несколько единиц оборудования.

Are there other words for “equipment” in Russian, and how do they differ from оборудование?

Yes. Common synonyms:

Аппаратура: often refers to electronic or technical apparatus (e.g. lab or broadcast equipment).
Техника: covers machinery, appliances, technical devices (often consumer or industrial machinery).
Оборудование is the broadest term, covering any set of machines, tools, installations used for work or production.

How do you pronounce оборудование, and where’s the stress?

It’s pronounced [ɐbɐˈrudəvənʲɪje], with the stress on the third syllable: обору́дование.