Kurier doręczy osiem przesyłek.

Kurier is in the nominative singular because it is the subject of the sentence — the person doing the action.

Its dictionary form is also kurier. The verb doręczy agrees with it in 3rd person singular.

Because doręczy comes from the perfective verb doręczyć.

In Polish, perfective verbs do not normally describe an action happening right now. Their present-looking forms usually have future meaning. So:

• doręczy = will deliver / will complete the delivery
• imperfective doręcza = delivers, is delivering, or delivers regularly, depending on context

So Kurier doręczy osiem przesyłek refers to a completed future action.

The infinitive is doręczyć.

So the pattern is:

• doręczyć = infinitive
• doręczy = he/she/it will deliver

This is a very common Polish pattern with verbs ending in -ić / -yć or similar-looking forms, where the finite form is a bit shorter than the infinitive.

Because after numerals 5 and higher, Polish usually puts the counted noun in the genitive plural.

So:

• przesyłka = one parcel / shipment
• przesyłki = parcels / shipments
• przesyłek = genitive plural

Since osiem means eight, the correct phrase is osiem przesyłek.

This is one of the most important number rules in Polish:

• 2, 3, 4 often take nominative/accusative plural
• 5 and above usually take genitive plural

Yes. That is the important distinction:

• function: the whole phrase osiem przesyłek is the direct object
• form: inside that phrase, the noun przesyłek appears in the genitive plural

So even though English speakers expect a direct object to be simply accusative, Polish numeral phrases work differently. After osiem, the noun must be in genitive plural.

Osiem is the basic form of the numeral, and it is the normal choice here.

Ośmiu is a declined form used in some other grammatical contexts. For example, you may see it after certain prepositions or in other case environments.

So for this sentence, osiem przesyłek is the standard form.

It agrees with kurier, because kurier is the subject.

That is why the verb is 3rd person singular:

• kurier doręczy = the courier will deliver

The phrase osiem przesyłek is the object, so it does not control the verb form here.

Yes. Polish word order is more flexible than English because case endings help show what each word is doing.

The neutral, standard order here is:

• Kurier doręczy osiem przesyłek.

But you could also change the order for emphasis, for example:

• Osiem przesyłek doręczy kurier.
• Osiem przesyłek kurier doręczy.

These versions still mean roughly the same thing, but the focus changes. The original sentence is the most natural if you are just stating the fact plainly.

Because Polish has no articles.

So kurier can mean:

• a courier
• the courier

and osiem przesyłek can mean:

• eight parcels
• the eight parcels

The exact meaning depends on context, not on separate words like a or the.

The base form is przesyłka.

Here are the useful forms to connect:

• przesyłka = singular
• przesyłki = plural
• przesyłek = genitive plural

So in osiem przesyłek, you are seeing the form required after the numeral osiem.