Вона зашила дірку за допомогою нитки.

Because дірку is in the accusative case, which marks the direct object of the verb.

The verb зашила means sewed up / stitched up, and the thing being sewn up is дірка (a hole), so it changes:

• nominative: дірка
• accusative: дірку

This is very common with feminine nouns ending in -а:

• книга → книгу
• машина → машину
• дірка → дірку

Зашила comes from зашити, which means to sew up, to stitch closed, or to mend by sewing.

By contrast, шила from шити usually means was sewing or sewed in a more general sense.

So:

• шити = to sew
• зашити = to sew up / stitch closed

In this sentence, the idea is not just that she was sewing, but that she repaired or closed the hole, so зашила is the natural choice.

In Ukrainian, past tense verbs agree in gender and number.

Here the subject is вона (she), so the verb takes the feminine singular past form:

• він зашив = he sewed up
• вона зашила = she sewed up
• воно зашило = it sewed up
• вони зашили = they sewed up

So зашила tells you that the subject is feminine singular.

За допомогою means with the help of or more naturally in many contexts by means of / using.

So за допомогою нитки literally means with the help of thread, but in natural English the sentence would usually be understood as using thread.

This is a fixed expression:

• за допомогою ножа = using a knife
• за допомогою комп’ютера = using a computer
• за допомогою нитки = using thread

It is a bit more formal or explicit than simply using the instrumental case alone.

Because the phrase за допомогою requires the noun after it to be in the genitive case.

So:

• nominative: нитка = thread
• genitive: нитки
• instrumental: ниткою

That is why the sentence says за допомогою нитки.

If you wanted to say with thread more directly, without за допомогою, you could use the instrumental:

• Вона зашила дірку ниткою.

That version is often more natural in everyday speech.

In many everyday situations, yes.

• Вона зашила дірку ниткою. = She sewed up the hole with thread.
• Вона зашила дірку за допомогою нитки. = She sewed up the hole by means of thread.

The version with ниткою sounds simpler and more natural in casual speech.
The version with за допомогою нитки is grammatically correct, but slightly more formal, more explicit, or a bit heavier stylistically.

So a learner should understand both, but probably use ниткою more often in normal conversation.

Вона is in the nominative case because it is the subject of the sentence.

The nominative form of the pronoun is used for who does the action:

• вона = she

Other forms of this pronoun include:

• її = her
• неї = her / of her / to her / with her, depending on the preposition and case

But here, since she is doing the sewing, the nominative вона is used.

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

The neutral order here is:

• Вона зашила дірку за допомогою нитки.

But you could also say:

• Дірку вона зашила за допомогою нитки.
• За допомогою нитки вона зашила дірку.

These alternatives shift focus or emphasis:

• starting with Дірку emphasizes what was sewn up
• starting with За допомогою нитки emphasizes the means used

Even though word order can change, the original sentence is the most straightforward and neutral.

Yes, дірка is a common everyday word for hole.

Examples:

• дірка в сорочці = a hole in a shirt
• дірка в шкарпетці = a hole in a sock
• дірка в стіні = a hole in the wall

There is also отвір, which often means opening, orifice, or aperture, and can sound more technical or formal. For a tear or hole in clothing, дірка is the usual word.

Then Ukrainian would usually use the imperfective verb шити / зашивати instead of the perfective зашити.

For example:

• Вона зашивала дірку. = She was sewing up the hole / She used to sew up the hole.
• Вона шила. = She was sewing.

But Вона зашила дірку means the action is viewed as completed: the hole got sewn up.

So this sentence uses the perfective aspect to show a finished result.

Нитки is pronounced approximately nyt-KY, with the stress on the second syllable: нитки́.

As for articles: Ukrainian has no words corresponding directly to English articles a/an and the. Context usually shows whether something is definite or indefinite.

So дірку could mean:

• a hole
• the hole

and нитки could mean:

• thread
• some thread
• the thread

In this sentence, English would usually say the hole if it is already known, but Ukrainian does not need a separate word for that.

Yes, depending on context, нитка can mean thread, and sometimes more broadly strand or line. But in sewing contexts, нитка very naturally means thread.

For example:

• швейна нитка = sewing thread
• нитка перлів = a string of pearls
• залізнична нитка can even be used in specialized contexts for a railway line or route

Here, because of зашила дірку, the meaning thread is the obvious one.

Yes, often you can.

Ukrainian often drops subject pronouns when the verb form already makes the subject clear enough from context. So:

• Зашила дірку за допомогою нитки.

can mean She sewed up the hole using thread, if the context already makes clear who she is.

However, keeping вона is perfectly fine, especially if you want to:

• make the subject explicit
• create contrast, as in She did it, not someone else
• give a full standalone sentence for learners

So both versions are possible.