Da li poznaješ protivnika?

Da li is a very common way to form a yes/no question in Serbian.

So:

• Poznaješ protivnika. = You know the opponent.
• Da li poznaješ protivnika? = Do you know the opponent?

It works a bit like English do/does when making questions, but it is not a direct word-for-word equivalent.

Poznaješ is the 2nd person singular present tense of poznavati / poznavati nekoga, meaning to know, be acquainted with, be familiar with.

It matches you:

• ja poznajem = I know
• ti poznaješ = you know
• on/ona poznaje = he/she knows

The form poznaš exists from a different verb, upoznati / poznati in certain contexts, but in ordinary speech, when you want to say know someone / be familiar with someone, poznavati and its present forms like poznaješ are what learners most often need here.

This is a very common learner question.

In Serbian:

• znati usually means to know a fact, to know how, or to be aware
• poznavati / poznavati nekoga means to know a person, to be acquainted with, or to know something well/familiarity

So:

• Znam odgovor. = I know the answer.
• Znam da je ovde. = I know that he is here.
• Znam da plivam. = I know how to swim.
• Poznajem Marka. = I know Marko.
• Poznajem ovaj grad. = I know this city / I’m familiar with this city.

In Da li poznaješ protivnika?, the idea is familiarity with a person, so poznaješ is the natural choice.

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

The base form is:

• protivnik = opponent (nominative)

But after a transitive verb like poznavati (to know), the object goes into the accusative:

• poznaješ protivnika = you know the opponent

Since protivnik is a masculine animate noun, its accusative singular usually looks like the genitive singular:

• nominative: protivnik
• accusative: protivnika

This is very normal for masculine animate nouns in Serbian.

In Serbian grammar, nouns referring to people are animate, and many nouns referring to animals are too.

Because protivnik means opponent and refers to a person, it is masculine animate. That is why:

• Vidim protivnika.
• Poznaješ protivnika.

use protivnika in the accusative, not protivnik.

Compare:

• Vidim sto. = I see the table.
  (sto is masculine inanimate, so accusative = nominative)
• Vidim čoveka. = I see the man.
  (čovek is masculine animate, so accusative changes)

Yes. Serbian can also form a yes/no question just by intonation, especially in speech.

So both of these are possible:

• Da li poznaješ protivnika?
• Poznaješ protivnika?

The version with da li is often clearer for learners because it explicitly marks the sentence as a question.

There is also another question pattern with li after the verb, for example:

• Poznaješ li protivnika?

That is also correct and quite common.

Not completely. Serbian word order is fairly flexible, though some versions sound more neutral than others.

The most neutral version here is:

• Da li poznaješ protivnika?

You may also hear:

• Poznaješ li protivnika?

A sentence like:

• Protivnika poznaješ?

is possible, but it gives special emphasis to protivnika, something like The opponent—you know him?

So the usual learner-safe order is the original one.

It is written as two words:

• da
• li

So the correct spelling is:

• Da li poznaješ protivnika?

not a single combined word.

Poznaješ is:

• 2nd person
• singular
• present tense

So it means you know when speaking to one person.

If you were addressing more than one person, or using polite you, you would say:

• Da li poznajete protivnika?

You would use poznajete instead of poznaješ:

• Da li poznajete protivnika?

This can mean either:

• Do you all know the opponent?
• Do you know the opponent? (formal/polite, speaking to one person)

So Serbian uses the same verb form for you plural and formal you singular, just like many European languages.

It can mean either, depending on context.

Poznavati often means:

• to know someone personally
• to be acquainted with
• to be familiar with

So Da li poznaješ protivnika? could mean:

• Do you know the opponent personally?
• Are you familiar with the opponent?

In a sports, debate, or competition context, it may simply mean Are you familiar with who the opponent is / what they are like?

Yes. This is a very useful pattern:

• Da li poznaješ Marka? = Do you know Marko?
• Da li poznaješ profesora? = Do you know the professor?
• Da li poznaješ ovog čoveka? = Do you know this man?

The structure is:

• Da li + verb + direct object?

Just remember that if the object is a masculine animate noun, it will usually take the accusative form, as protivnika does here.