Tražim ključ, ali ključ nije ovde.

Because ključ is a masculine inanimate noun, and in Serbian the accusative singular of masculine inanimate nouns is usually the same as the nominative singular.

So in:

• Tražim ključ = I am looking for the key
• ključ nije ovde = the key is not here

the first ključ is the direct object of tražim, so it is in the accusative. The second ključ is the subject of nije, so it is in the nominative.

Even though the cases are different in function, the form happens to look the same.

Serbian does not have articles like English a/an and the.

So ključ can mean:

• a key
• the key

The exact meaning depends on context. In this sentence, English would usually translate it as the key, but Serbian simply uses ključ with no article.

Tražim is the first person singular present tense of tražiti, meaning to look for or to search for.

So:

• tražim = I am looking for / I look for

The ending -m often marks I in the present tense.

Examples:

• Tražim knjigu. = I’m looking for a book.
• Tražim telefon. = I’m looking for the phone.

In Serbian, the verb biti (to be) has special negative forms that are written as single words:

• nisam = I am not
• nisi = you are not
• nije = he/she/it is not
• nismo = we are not
• niste = you all are not
• nisu = they are not

So:

• ključ nije ovde = the key is not here

You do not normally say ne je.

Serbian often repeats the noun where English might prefer a pronoun.

So this is perfectly natural:

• Tražim ključ, ali ključ nije ovde.

You could also say:

• Tražim ključ, ali on nije ovde.

That means I’m looking for the key, but it is not here.

However, repeating ključ can sound clearer and more direct, especially in simple sentences for emphasis or clarity.

Because ali means but, and in Serbian it is normally separated by a comma when it connects two clauses.

So:

• Tražim ključ, ali ključ nije ovde.

This is standard punctuation.

You will very often see a comma before conjunctions like ali when they join full thoughts.

Both can often mean here, but they are not always identical.

• ovde = here, near the speaker
• tu = there / here, often near the listener or in a contextually known place

In many everyday situations, both are possible, but ovde is a very straightforward choice for here.

So:

• ključ nije ovde = the key is not here

This strongly points to not here, in this place.

Yes. Serbian word order is more flexible than English, because case endings help show grammatical roles.

The neutral, straightforward order here is:

• Tražim ključ, ali ključ nije ovde.

But other orders are possible for emphasis, for example:

• Ključ tražim, ali ključ nije ovde.
• Tražim ključ, ali nije ovde.

These can sound more marked or context-dependent. For learners, the original sentence is the safest and most neutral version.

A rough pronunciation guide:

• ključ sounds approximately like klyooch

The tricky parts are:

• lj: a soft sound, somewhat like the lli in million, but not exactly the same
• č: like ch in church, but a bit firmer

So the whole word is one syllable: ključ.

If pronunciation is hard at first, that is normal—lj is one of the sounds English speakers often need time to practice.

Both exist, depending on the regional standard.

• ovde is common in Serbian, especially in the Ekavian standard
• ovdje appears in Ijekavian varieties and in closely related standards

So in standard Serbian, especially the variety most learners first meet, ovde is completely normal.

Usually, yes. In this sentence, tražim ključ most naturally means:

• I’m looking for the key
• I’m searching for the key

It can describe an action happening now or around now.

The verb tražiti is imperfective, which is the normal choice for an ongoing search or repeated action. That is why it fits naturally in a sentence like this.