Learn Hardcore Polish: On często zagląda do skrzynki na listy.

Imperfective: zaglądać – ongoing, repeated, or habitual actions
- On często zagląda do skrzynki na listy. – He often looks/checks.
Perfective partner: zajrzeć – a single, completed act
- On zajrzał do skrzynki na listy. – He took a look in / peeked into the mailbox (once; it’s done).

So:

Habit / repeated action → zaglądać
One completed act → zajrzeć

3. Why is it do skrzynki, not something like w skrzynkę?

In Polish, the verb zaglądać normally takes the preposition do:

zaglądać do
- genitive = look into (a place, container, room, etc.)

Examples:

zaglądać do szafy – to look into the wardrobe
zaglądać do lodówki – to look into the fridge
zaglądać do skrzynki – to look into the box/mailbox

So:

do is required by the verb here
and do always takes the genitive case, which is why we have skrzynki, not skrzynka.

4. What case is skrzynki and how is it formed from skrzynka?

The base noun is:

skrzynka – a box; here: a mailbox / letterbox

After do, we must use the genitive case:

nominative (dictionary form): skrzynka
genitive singular: skrzynki

Pattern (feminine noun, -a ending):

-a → -i in genitive singular
- kolega → kolegi
- szafka → szafki
- skrzynka → skrzynki

So do skrzynki literally = into/of the box → into the mailbox.

5. Why is it na listy and not something like listów or na listach?

Skrzynka na listy is a fixed pattern:

skrzynka na listy = a box for letters / a mailbox

Here:

na
- accusative can express purpose or intended use:
  - szklanka na wodę – a glass for water
  - buty na zimę – shoes for winter
  - torba na zakupy – a bag for shopping
  - skrzynka na listy – a box for letters

Listy is accusative plural of list (letter):

nominative plural: listy
accusative plural: listy (same form here)

So na listy = for letters, not of letters; that’s why it’s not listów (genitive) or na listach (locative: on the letters).

6. Is skrzynka na listy one unit meaning "mailbox"? Are there alternatives?

Yes. Skrzynka na listy is a common way to say mailbox / letterbox, especially the private one on a house, door, or gate.

Other possibilities you may see:

skrzynka pocztowa – literally postal box (can be either your home mailbox or an official red/blue street mailbox)
skrzynka alone – often clear from context:
- Idę do skrzynki. – I’m going to the mailbox.

In this sentence, do skrzynki na listy = to the mailbox (for letters).

7. Where does często usually go in a sentence? Could I move it?

Często = often, an adverb of frequency.

Default, very natural position:

On często zagląda do skrzynki na listy.

Other possible placements (all grammatically correct, with slight emphasis differences):

On zagląda często do skrzynki na listy.
(neutral, similar meaning; adverb moved after the verb)
Często on zagląda do skrzynki na listy.
(puts more emphasis on often, sometimes slightly contrastive: HE is often the one who checks.)

In practice, the original word order is the most neutral and common.

8. Do I need the pronoun On? Can I just say Często zagląda do skrzynki na listy?

You can drop the subject pronoun in Polish if it’s clear from context who you’re talking about:

On często zagląda do skrzynki na listy.
Często zagląda do skrzynki na listy.

Both are correct.

Differences:

Without On – more typical, natural flow in Polish conversation when the subject is known.
With On – can:
- introduce a new topic: On często zagląda... – He often checks...
- contrast with someone else: On często zagląda, a ona prawie nigdy. – He often checks, and she almost never does.

9. If I change On to Ona, does the verb form zagląda change?

No, the verb stays the same:

On zagląda... – He looks/peeks...
Ona zagląda... – She looks/peeks...

In the present tense, 3rd person singular has one form for all genders:

on / ona / ono zagląda – he / she / it looks/peeks

The pronoun changes, but zagląda does not.

10. How would I naturally translate this sentence into English?

Common, natural translations:

He often checks the mailbox.
He often looks in the mailbox.
He often looks into the mailbox.

If you want a very literal, image-focused version:

He often peeks into the letterbox.

In everyday English, "checks the mail/mailbox" is usually the most idiomatic.

11. Why is the present tense used in Polish for a habitual action ("he often checks")?

Polish present tense covers both:

what is happening right now
and habitual / repeated actions

So:

On często zagląda do skrzynki na listy.
= He often checks the mailbox. (habit)

English has to show this habit with adverbs like often, usually, always, etc. Polish doesn’t need a special tense; the present form zagląda plus często is enough.

12. How does zaglądać compare to sprawdzać or patrzeć?

All three are related but not identical:

zaglądać (do czegoś) – to peek / look into (a place/container)
- suggests a short, physical look inside, often to check something
- zaglądać do skrzynki / do szafy / do lodówki
sprawdzać – to check / verify
- more neutral, functional; doesn’t emphasize physically looking
- On często sprawdza skrzynkę na listy. – He often checks the mailbox (maybe by opening it, maybe by asking someone, etc.)
patrzeć (na coś) – to look at something (surface, direction), not into
- patrzeć na obraz – look at a painting
- patrzeć na skrzynkę – look at the mailbox (from outside), not necessarily inside it

So this sentence emphasizes the act of peeking into the mailbox, not just looking at it from a distance.

13. Why does do take the genitive, but na here takes the accusative?

Prepositions in Polish are fixed with certain cases:

do always takes genitive:
- do domu, do sklepu, do skrzynki
na can take accusative or locative, depending on meaning:
- na
  - accusative → direction or purpose:
    - iść na pocztę – go to the post office
    - torba na zakupy – bag for shopping
    - skrzynka na listy – box for letters (purpose)
- na
  - locative → location (where something is):
    - na stole – on the table
    - na poczcie – at the post office

In skrzynka na listy we’re in the purpose pattern, so na + accusative → na listy.

14. What are the main forms of list I should know to understand listy here?

Base noun:

list – a letter (piece of mail)

Key forms:

singular:
- nominative: list – a letter
- genitive: listu – of a letter
- accusative: list – a letter (same as nominative)
plural:
- nominative: listy – letters
- genitive: listów – of letters
- accusative: listy – letters (same as nominative)

In skrzynka na listy:

listy is accusative plural, governed by na (purpose: for letters).

15. Can I change the word order more drastically, and will it still be correct?

Polish word order is fairly flexible. All of these are grammatically correct:

On często zagląda do skrzynki na listy. – neutral.
On zagląda do skrzynki na listy często. – adverb at the end; slightly marked, but possible.
Często on zagląda do skrzynki na listy. – emphasizes often or contrasts the subject.
Do skrzynki na listy on często zagląda. – emphasizes the place (It’s the mailbox that he often checks).

They all mean roughly the same thing; shifting elements mainly changes emphasis and rhythm, not the core meaning.