Poznajem domaćina.

Because Serbian often drops subject pronouns when they are already clear from the verb form.

In poznajem, the ending -em shows that the subject is I. So:

• Poznajem domaćina. = I know the host.
• Ja poznajem domaćina. also means I know the host, but ja adds emphasis, as in I know the host.

This is very common in Serbian.

• poznajem = I know / I am acquainted with
• domaćina = the host (in this sentence’s case form)

So the structure is basically:

• poznajem = verb
• domaćina = direct object

Because domaćina is in the accusative case, which is used for the direct object of the verb.

The base form is:

• domaćin = host (nominative singular)

But in I know the host, the host is the object, so Serbian changes the form:

• nominative: domaćin
• accusative: domaćina

This happens because domaćin is a masculine animate noun. In Serbian, masculine animate nouns usually have:

• nominative singular: -in here
• accusative singular: often matching the genitive, so domaćina

Because Serbian usually uses poznavati / poznajem for knowing a person, while znati is more often used for knowing facts, information, or how to do something.

So:

• Poznajem Marka. = I know Mark.
• Znam odgovor. = I know the answer.
• Znam da plivam. = I know how to swim.

For people, poznajem is the natural choice.

The dictionary form is poznavati.

So:

• infinitive: poznavati = to know, to be acquainted with
• poznajem = I know

This is the 1st person singular present tense form.

Yes. Poznajem is present tense, 1st person singular:

• ja poznajem = I know

In Serbian, the present tense here usually expresses a current state, not just something happening right now. So it means that at present, you are acquainted with that person.

Yes. Serbian word order is more flexible than English because the case ending already shows the object.

The most neutral order is:

• Poznajem domaćina.

But you may also hear:

• Domaćina poznajem.

That version puts more emphasis on domaćina. It can sound like The host is the one I know or I do know the host depending on context.

So the default order is best for learners, but other orders are possible.

Not always. Domaćin can have a few related meanings depending on context, such as:

• host
• master of the house
• sometimes householder
• in some contexts, even landlord or owner/keeper of a household

In your sentence, the exact English meaning depends on context, but host is a very common translation.

A rough English-style guide is:

• do-ma-chi-na

The letter ć is a soft sound, somewhat like a very soft ch, but not exactly the same as English ch. It is softer and more palatal.

Also:

• j in Serbian is pronounced like English y
• so poznajem sounds roughly like poz-na-yem

These are only approximations, but they can help at the beginning.

Serbian does not have articles like a and the, so domaćina by itself does not directly mark definiteness the way English does.

Depending on context, it could be understood as:

• the host
• a host

However, in many simple translations, English uses the host because that often sounds more natural in context. The exact choice comes from the situation, not from an article in Serbian.

The feminine form is usually domaćica.

So:

• domaćin = male host
• domaćica = female host

If the sentence were about a female host, you might get:

• Poznajem domaćicu. = I know the female host.

Notice that the object case changes differently there too:

• nominative: domaćica
• accusative: domaćicu