Оригинальность текста проверили.

Even though оригинальность looks like nominative singular, in this sentence it is actually the direct object of the verb проверили.

That is possible because оригинальность is an inanimate feminine noun, and for many feminine nouns the accusative singular has the same form as the nominative singular.

So in:

Оригинальность текста проверили.

• оригинальность = direct object, accusative singular
• текста = dependent noun, genitive singular
• проверили = they checked / someone checked

A more literal structure is:

[They] checked the originality of the text.

Текста is genitive singular because it depends on оригинальность:

• оригинальность текста = the originality of the text

This is a very common Russian pattern: one noun modifies another by going into the genitive.

Other similar examples:

• автор книги = the author of the book
• начало фильма = the beginning of the film
• проверка документа = the checking of the document

So текста is not the direct object of the verb. It belongs to the noun phrase оригинальность текста.

This is a very common Russian construction. The verb in the 3rd person plural can be used when:

• the doer is unknown
• the doer is unimportant
• the speaker does not want to name the doer

So проверили literally means they checked, but it often functions like English:

• they checked it
• someone checked it
• sometimes even something close to a passive: it was checked

In this sentence, the focus is on the action and result, not on who performed it.

Yes, very naturally.

Although Russian does not use a passive form here, English often prefers one in this kind of context. So depending on context, you might translate it as:

• They checked the originality of the text.
• The text’s originality was checked.
• The text was checked for originality.

All of these can fit, depending on what sounds best in context.

So the Russian sentence is grammatically active, but in meaning it can overlap with an English passive translation.

Both are possible, but the word order changes the focus.

• Проверили оригинальность текста.
  Neutral: They checked the originality of the text.

• Оригинальность текста проверили.
  The object is moved to the front for emphasis or contrast. It can suggest something like:
  As for the text’s originality, they checked it.

Fronting the object often makes it feel more topical, contrastive, or connected to previous context.

For example, if someone asks:

• А оригинальность текста проверили?
  And did they check the text for originality?

A natural reply could be:

• Оригинальность текста проверили.

Проверили is the perfective past form of проверить.

Russian aspect here:

• проверять = imperfective, process/repetition/general fact
• проверить = perfective, completed action/result

So:

• проверяли = they were checking / they checked (process, repeated, or without focus on result)
• проверили = they checked, and the action is complete

In this sentence, the point is that the check was carried out successfully / completed, so perfective is natural.

Because Russian expresses the idea a little differently here.

English often says:

• check the text for originality

Russian can say that too in other ways, but this sentence literally focuses on the originality, not directly on the text:

• проверили оригинальность текста
  = checked the originality of the text

So the direct object is оригинальность, and текста only specifies whose originality.

This is a good example of how Russian and English often package the same meaning differently.

Yes, absolutely.

That is another very natural way to express a similar idea:

• Проверили текст на оригинальность.
  = They checked the text for originality.

Compare the two:

• Проверили оригинальность текста.
  Focus on the originality
• Проверили текст на оригинальность.
  Focus on the text

Both are correct and common. The difference is mainly one of structure and emphasis.

Russian often omits subjects when they are obvious, generic, or not important.

Since the verb form проверили already shows 3rd person plural, Russian does not need они unless the speaker wants emphasis or contrast.

So:

• Они проверили оригинальность текста.
  = They checked the originality of the text.
  This explicitly mentions they.

• Оригинальность текста проверили.
  = The originality of the text was checked / They checked the originality of the text.
  This sounds more impersonal and often more natural.

Yes, it is a normal noun meaning originality.

It comes from the adjective:

• оригинальный = original

And the noun:

• оригинальность = originality

In many modern contexts, especially academic or online, оригинальность текста often refers specifically to whether a text is original and not plagiarized.

So depending on context, it may mean:

• originality in a general sense
• uniqueness
• plagiarism-related originality score

The dictionary forms are:

• оригинальность → оригинальность
• текста → текст
• проверили → проверить

More specifically:

• оригинальность = noun, feminine, singular
• текст = noun, masculine
• проверить = verb, perfective

And the forms in the sentence are:

• оригинальность = accusative singular
• текста = genitive singular
• проверили = past tense, plural

Yes. Russian past tense does not map exactly onto English tense choices.

Проверили is a past form, but depending on context English may translate it as:

• They checked the originality of the text.
• They have checked the originality of the text.

If the speaker is emphasizing the present relevance of the completed action, English often uses the present perfect. Russian still just uses the ordinary past tense form.

So the exact English tense depends on context, not only on the Russian verb form.