Doręczenie się opóźniło.

Here doręczenie means delivery or the act of delivering. It is a fairly formal word.

Depending on context, it can refer to:

• postal/courier delivery
• delivery of a document
• even service in a legal/official sense

In everyday speech about a package, Polish speakers often use dostawa or przesyłka instead.

It is a noun.

More specifically, it is a verbal noun formed from the verb doręczyć (to deliver). So it works like English words such as delivery or delivery of something, not like a finite verb.

In this sentence, doręczenie is the subject:

• Doręczenie = the delivery
• się opóźniło = got delayed / was delayed

Because Polish past-tense verbs agree with the subject in gender and number.

Doręczenie is a neuter singular noun, so the verb must also be neuter singular:

• opóźnił się — masculine singular
• opóźniła się — feminine singular
• opóźniło się — neuter singular

Compare:

• List opóźnił się. — The letter got delayed.
• Przesyłka opóźniła się. — The shipment got delayed.
• Doręczenie opóźniło się. — The delivery got delayed.

Not really. In this sentence, się is not best understood as literal itself.

The verb opóźnić się means to become delayed / to be delayed / to get delayed. It is a very common Polish pattern where się helps make the verb intransitive.

Compare:

• Firma opóźniła doręczenie. — The company delayed the delivery.
• Doręczenie się opóźniło. — The delivery got delayed.

So się here is part of the verb expression opóźnić się, not a separate word you would normally translate as itself.

It is past tense and perfective aspect.

The base verb here is opóźnić się (perfective), which means that the sentence presents the delay as a completed event: the delay happened.

So the sentence can correspond to English:

• The delivery was delayed.
• The delivery got delayed.
• The delivery has been delayed.

Which English version sounds best depends on context.

If you wanted an ongoing or repeated idea, Polish would use the imperfective verb opóźniać się, for example:

• Doręczenie się opóźnia. — The delivery is being delayed / is running late.
• Doręczenie się opóźniało. — The delivery was getting delayed / was delayed repeatedly

Yes, it is grammatical, but many speakers would find Doręczenie opóźniło się more neutral in modern Polish.

Both are possible:

• Doręczenie się opóźniło.
• Doręczenie opóźniło się.

Polish word order is more flexible than English, and się can move around, although it normally does not go at the very beginning of a clause.

So for a learner, Doręczenie opóźniło się is probably the safest, most natural version to use.

Because Polish often uses reflexive/intransitive structures where English prefers a passive.

Literally, Polish has something like:

• The delivery delayed itself / got delayed

But natural English usually says:

• The delivery was delayed

So the Polish sentence is not a classic passive form, but in translation it often becomes one.

Yes. That is a correct alternative.

• Doręczenie się opóźniło / Doręczenie opóźniło się — The delivery got delayed
• Doręczenie zostało opóźnione — The delivery was delayed

The difference is mainly in style and nuance:

• opóźniło się sounds more natural and event-focused
• zostało opóźnione is more explicitly passive and often sounds more formal or official

In notices, tracking messages, or bureaucratic language, zostało opóźnione may be common.

Not especially. It is correct, but it sounds fairly formal or technical.

In everyday conversation, people might more often say:

• Dostawa się opóźniła. — The delivery got delayed.
• Przesyłka się opóźniła. — The shipment/package got delayed.
• Paczka się spóźnia. — The package is late.

So doręczenie is fine, but it may sound more like the language of logistics, postal services, or official communication.

Because Polish has no articles. There is no direct equivalent of English a/an/the used in normal sentences.

So doręczenie can mean:

• delivery
• the delivery

Context tells you which is meant.

In this sentence, English naturally uses the:

• The delivery was delayed.

But Polish simply says:

• Doręczenie się opóźniło.