Ja uvek nosim ključ u torbi.

Yes. In Serbian, subject pronouns are often omitted because the verb ending already shows who is doing the action.

• nosim = I carry / I wear / I keep on me
• so Ja nosim and just Nosim both mean I carry

Here, ja can be used for:

• emphasis: I always carry the key in my bag
• contrast: I always carry it, but someone else doesn’t

In neutral speech, Uvek nosim ključ u torbi would be very natural.

No. Serbian word order is fairly flexible compared with English. The sentence Ja uvek nosim ključ u torbi is natural, but other orders are also possible depending on emphasis.

For example:

• Uvek nosim ključ u torbi. = neutral, common
• Ključ uvek nosim u torbi. = emphasis on the key
• U torbi uvek nosim ključ. = emphasis on in the bag

The basic meaning stays the same, but the focus changes.

Uvek means always.

It is an adverb, so it describes how often the action happens:

• Ja uvek nosim ključ u torbi. = I always carry the key in my bag.

You may also see uvijek. That is the Ijekavian form, while uvek is Ekavian. Both mean the same thing.

Here, nosim means I carry or I keep with me.

The verb is nositi, which can mean:

• to carry
• to wear
• sometimes more generally to have on oneself / to bring along

So:

• Nosim torbu. = I’m carrying a bag.
• Nosim kaput. = I’m wearing a coat.

In your sentence, because of ključ u torbi, the meaning is clearly I carry / keep the key in my bag.

It is present tense, first person singular:

• ja nosim = I carry

But in Serbian, just like in English, the present tense can describe a habitual action:

• Ja uvek nosim ključ u torbi.
• literally present tense, but meaning I always carry / I always keep

So this is not necessarily happening right now at this exact moment; it can describe a regular habit.

Because ključ is the direct object of the verb, so it is in the accusative case. However, for many inanimate masculine nouns, the accusative singular looks exactly the same as the nominative singular.

So:

• nominative: ključ = key
• accusative: ključ = key

That is why there is no visible change here.

Compare:

• Vidim ključ. = I see the key.
• Imam ključ. = I have the key.

Because u can take different cases depending on the meaning.

• u + locative = in / inside a place, showing location
• u + accusative = into a place, showing movement toward it

Here, the key is located in the bag, so Serbian uses locative:

• u torbi = in the bag

Compare:

• Ključ je u torbi. = The key is in the bag.
• Stavljam ključ u torbu. = I am putting the key into the bag.

So:

• u torbi = location
• u torbu = motion into

Torbi is locative singular of torba.

The noun torba is feminine, and its basic form is:

• nominative singular: torba = bag

After u when it means location, Serbian uses the locative:

• u torbi = in the bag

For many feminine nouns ending in -a, the locative singular ends in -i:

• torba → u torbi
• škola → u školi
• soba → u sobi

Because Serbian does not have articles like English a and the.

So:

• ključ can mean a key or the key
• torba can mean a bag or the bag

The exact meaning depends on context.

In your sentence, English might translate it as:

• I always carry a key in my bag or
• I always carry the key in my bag

Both are possible depending on the situation.

Yes, nosim can also mean I wear.

For example:

• Nosim jaknu. = I’m wearing a jacket.
• Nosim naočare. = I wear glasses.

You know it means carry / keep here because of the object and phrase:

• ključ = key
• u torbi = in the bag

A key is not something you wear in a bag, so the context makes carry / keep the natural meaning.

Yes, absolutely. In natural English, that is often the best translation.

Depending on context, Ja uvek nosim ključ u torbi can suggest:

• I always carry the key in my bag
• I always keep the key in my bag
• I always have the key in my bag

Serbian often uses a verb in a way that overlaps with several natural English phrasings.

A rough pronunciation guide:

• ključ ≈ klyooch

  • lj is a soft sound, a bit like the lli in some pronunciations of million, but not exactly
  • č sounds like ch in church

• torbi ≈ TOR-bee

  • the r is trilled or tapped
  • i is like ee in see
• uvek ≈ OO-vek
• nosim ≈ NO-seem

A very rough full pronunciation:

• Ja uvek nosim ključ u torbi.
• ya OO-vek NO-seem klyooch oo TOR-bee

Yes. That would mean I always carry the key in my own/my bag more explicitly.

• u torbi = in the bag / in my bag, if context makes it clear
• u svojoj torbi = in my own bag

Serbian often leaves out possessives when they are obvious from context, especially with things closely connected to the speaker.

So u torbi is completely natural if it is already clear whose bag it is.

Yes, several useful Serbian patterns appear in just one sentence:

• subject pronoun can be omitted: (Ja) uvek nosim...
• present tense can describe a habit: uvek nosim
• masculine inanimate accusative may look unchanged: ključ
• u + locative shows location: u torbi
• no articles: no separate words for a/the
• word order is flexible: the same idea can be rearranged for emphasis

So this is a very good sentence for noticing how Serbian grammar works in everyday speech.