Корректор закончил корректуру.

Because корректура is the direct object of the verb закончил (finished), so it has to be in the accusative case.

• Nominative: корректура
• Accusative: корректуру

This is a very common pattern in Russian: a transitive verb takes its object in the accusative.

For example:

• читать книгу = to read a book
• писать письмо = to write a letter
• закончить корректуру = to finish the proofreading

Корректор usually means proofreader or copy editor, depending on context. It is a person whose job is to check text for mistakes.

It comes from the same general root as English words like correct and correction, so it is fairly easy to recognize.

Grammatically, корректор is a masculine noun.

Корректура usually refers to proofreading or proof correction, especially in publishing or editing contexts.

So in this sentence, it means something like:

• the proofreading work
• the correction of a text before publication

It is a feminine noun:

• nominative: корректура
• accusative: корректуру

They are related words built from the same root:

• корректор = the person who corrects
• корректура = the proofreading/correction work

Russian often forms related nouns this way, just as English has related pairs like:

• editor / editing
• translator / translation

So the similarity is completely normal and useful for vocabulary building.

In the past tense, Russian verbs agree with the subject in gender and number.

Here the subject is корректор, which is masculine singular, so the verb is:

• закончил = masculine singular past

Compare:

• Корректор закончил корректуру. = The proofreader finished the proofreading.
• Корректорша закончила корректуру. = The female proofreader finished the proofreading.
• Корректоры закончили корректуру. = The proofreaders finished the proofreading.

Both кончить and закончить can mean to finish, but закончить is usually the safer and more neutral choice in standard Russian.

So:

• закончить работу = to finish work
• закончить книгу = to finish a book
• закончить корректуру = to finish the proofreading

A learner will hear закончить very often in everyday and formal speech. It is generally the best verb to use for finish.

Закончил is perfective.

Russian uses the perfective aspect when the action is seen as completed or brought to an end. Since the sentence says the proofreading was finished, perfective is the natural choice.

Compare:

• заканчивал = was finishing / used to finish / finished in an ongoing sense
• закончил = finished, completed

So this sentence presents the action as a completed fact.

The infinitive is закончить.

Here is the basic relationship:

• закончить = to finish
• закончил = finished (masculine singular past)

This is a useful pattern to remember:

• infinitive ending -ить
• past masculine often ending -ил

For example:

• говорить → говорил
• решить → решил
• закончить → закончил

Yes. Russian word order is more flexible than English because case endings show grammatical roles.

The neutral order here is:

• Корректор закончил корректуру.

But you could also say:

• Корректуру закончил корректор.

That version puts more emphasis on корректуру or sounds more contrastive, as if answering Who finished the proofreading?

So the original sentence is the most straightforward, neutral version.

You can tell mainly from the case forms.

• Корректор is in the nominative case, so it is the subject.
• Корректуру is in the accusative case, so it is the direct object.

Even if the word order changes, the cases still tell you the roles.

That is one of the most important things to get used to in Russian: endings often matter more than position.

The stress is:

• корре́ктор
• корректу́ра
• зако́нчил

Stress is important in Russian because it is not always predictable and can affect pronunciation a lot. It is worth learning vocabulary together with stress whenever possible.