Learn Hardcore Croatian: Poznajem sve susjede u našem susjedstvu. - I know all the neighbors in our neighborhood.

znati – to know facts, information, or how to do something
- Znam odgovor. – I know the answer.
- Znam plivati. – I can swim / I know how to swim.
poznavati – to know a person (or place) in the sense of being familiar with them
- Poznajem Marka. – I (personally) know Mark.
- Poznajem ovaj grad. – I know this city (I’m familiar with it).

In Poznajem sve susjede u našem susjedstvu, you are talking about personal familiarity with people (your neighbors), so poznavati is the natural choice. Znam sve susjede is sometimes said in speech, but it sounds less precise and more like “I know who they are / I know about them” than “I know them personally.”

What is the infinitive and full conjugation of poznajem?

The infinitive is poznavati (to know, to be familiar with, usually with people or places).

Present tense (imperfective, ongoing/habitual action):

ja poznajem – I know
ti poznaješ – you (sg., informal) know
on / ona / ono poznaje – he / she / it knows
mi poznajemo – we know
vi poznajete – you (pl. or formal) know
oni / one / ona poznaju – they know

In the sentence, poznajem is 1st person singular, present tense: I know.

Is there a perfective partner to poznavati, and when would I use it?

Yes. The usual perfective partners are:

poznati – to get to know / to have come to know (less common in everyday speech)
More commonly in practice: upoznati (se) – to meet / to get to know (often for the first time)

Compare:

Dugo ga poznajem. – I have known him for a long time. (ongoing familiarity)
Upoznao sam ga prošle godine. – I met / got to know him last year. (one completed event)

In your sentence, you want a general, ongoing state (“I know all the neighbors”), so the imperfective poznavati → poznajem is correct.

Why is it sve susjede and not svi susjedi?

This is a case (grammar) issue.

svi susjedi is nominative plural (subject form):
- Svi susjedi su ljubazni. – All the neighbors are kind.
sve susjede is accusative plural (direct object form), which is needed after a verb like poznajem:
- Poznajem sve susjede. – I know all the neighbors.

So:

svi → subject (“all” doing the action)
sve → object with masculine animate nouns in the accusative plural

In this sentence, susjede are the object of poznajem, so you must say sve susjede.

Why does susjed become susjede here?

Susjed (neighbor) is a masculine noun. Its singular and plural forms (most relevant ones) are:

Singular

Nominative: susjed – neighbor (as subject)
Accusative: susjeda – neighbor (as object)

Plural

Nominative: susjedi – neighbors (as subject)
Accusative: susjede – neighbors (as object)

Because susjede is the direct object of poznajem, it must be in accusative plural, which is susjede. That’s why we say:

Poznajem susjede. – I know (the) neighbors.

Which case is susjede in, and why does poznajem need that case?

Susjede is in the accusative plural.

In Croatian, the direct object of a verb (the thing or person directly affected by the action) is normally in the accusative. The verb poznavati / poznajem takes a direct object, so its object must be in the accusative:

Poznajem koga? – sve susjede → accusative plural
Vidim koga? – prijatelja (my friend) → accusative singular

So the structure is:

Poznajem (verb) + sve susjede (direct object in accusative).

Why is it u našem susjedstvu, not u naše susjedstvo?

The preposition u can be used with two different cases, depending on the meaning:

u + locative → “in / inside” (static location)
- u našem susjedstvu – in our neighborhood
u + accusative → “into” (movement towards the inside)
- u naše susjedstvo – into our neighborhood (movement)

In your sentence, you are talking about where the neighbors are, not about moving anywhere, so you need the locative:

u našem susjedstvu – in our neighborhood (locative)
Idem u naše susjedstvo. – I’m going into our neighborhood (accusative)

What form is našem susjedstvu exactly? Why našem and not naša or naš?

Susjedstvo (neighborhood) is a neuter noun. In u našem susjedstvu, it’s in the locative singular.

susjedstvo – nominative singular
u susjedstvu – in the neighborhood (locative singular)

The possessive naš (our) must agree in gender, number, and case with the noun it modifies:

Gender: neuter
Number: singular
Case: locative

The neuter dative/locative form of naš is našem. So:

naše susjedstvo – our neighborhood (nominative)
u našem susjedstvu – in our neighborhood (locative)

Is u našem susjedstvu dative or locative?

Formally, našem susjedstvu could look like dative or locative, because those two cases share the same endings in the neuter singular.

However, after the preposition u with the meaning “in / inside”, Croatian grammar says we are using the locative case.

So in this sentence you should think of it as locative:

u (lokativu) – in (somewhere): u našem susjedstvu

Can I change the word order, for example: U našem susjedstvu poznajem sve susjede?

Yes. Croatian word order is relatively flexible. All of the following are grammatical:

Poznajem sve susjede u našem susjedstvu.
U našem susjedstvu poznajem sve susjede.
Sve susjede poznajem u našem susjedstvu.

The differences are about emphasis and style, not grammar:

Starting with U našem susjedstvu puts more emphasis on the place.
Keeping Poznajem at the start sounds like a neutral, straightforward statement.

For a learner, the original order is perfectly natural and commonly used.

Can I drop u našem susjedstvu or sve and still be correct?

Yes, but the meaning changes slightly:

Poznajem sve susjede.
- I know all the neighbors (context would decide which neighborhood).
Poznajem susjede u našem susjedstvu.
- I know the neighbors in our neighborhood (not necessarily all of them).
Poznajem susjede.
- I know the neighbors. (Very vague: which neighbors, how many?)

The full sentence Poznajem sve susjede u našem susjedstvu is very explicit:
you personally know every neighbor in your neighborhood.

How do I pronounce poznajem and susjedstvu?

Approximate pronunciation for English speakers:

poznajem → POZ-nah-yem
- Stress on the first syllable: POZ
- po as in pot, zna like zna in snack
  - nah, jem like yem in yeti
    - em
susjedstvu → SOOS-yed-stvoo
- Stress on SU: SUS-jed-stvu
- su as in soon, sj is like an s followed by a soft y sound, jed like yed, stvu like stvoo

Individual neighbors: susjed → SOOS-yed.
Plural: susjede → SOOS-ye-de (stress on SU).

Is this sentence formal or informal? Does it sound natural?

The sentence Poznajem sve susjede u našem susjedstvu. is:

Completely neutral in style – neither very formal nor very slangy
Very natural and something you could easily say in everyday conversation
Appropriate in almost any context (talking to friends, family, colleagues, etc.)

It’s a good model sentence to remember for the pattern: Poznajem + (sve) + [accusative plural people] + u + [locative place].