Ranac mi je na leđima.

Mi is the unstressed dative form of ja (to me).

In this sentence, it does not mean to me in a literal English sense. It is a very common Serbian way to show whose body part or personal item is involved.

So Ranac mi je na leđima is literally something like:

The backpack is to-me on the back

but naturally it means:

The backpack is on my back.

This dative usage is very common with body parts and personal situations:

• Boli me glava. = My head hurts.
• Ruke su mi hladne. = My hands are cold.
• Knjiga mi je u torbi. = My book is in the bag.

So here mi marks the person concerned: my back / on me.

Because Serbian often avoids repeating possessives when the owner is already clear from context or from a dative pronoun like mi.

So:

• Ranac mi je na leđima sounds natural and idiomatic.
• Moj ranac je na mojim leđima is grammatical, but it sounds more explicit, heavier, and less natural in an everyday neutral context.

English often needs my, but Serbian often does not.

Je is the 3rd person singular present form of biti (to be).

It links the subject ranac with its location:

• Ranac je na leđima. = The backpack is on the back.

Because ranac is singular, the verb is singular:

• ranac → je

If the subject were plural, the verb would change:

• Rančevi su na leđima. = The backpacks are on the back.

Because Serbian uses different cases depending on whether you mean:

• location → where something is
• direction/motion → where something is going

With na:

• na + locative = on / at a place
• na + accusative = onto / to a place

Here the backpack is already located there, so Serbian uses the locative:

• na leđima = on the back

If you were talking about putting it onto your back, you would use accusative:

• Stavio sam ranac na leđa. = I put the backpack onto my back.

So:

• na leđima = static position
• na leđa = movement toward that position

Yes, but Serbian leđa is a plural-only noun. That means it has plural form even when it refers to what English calls the back as one body area.

Its basic form is:

• leđa = back

In the sentence, after na for location, it becomes locative plural:

• na leđima

This is something English speakers just have to get used to. A few body-related or object nouns in Serbian behave differently from their English equivalents.

Here leđima is in the locative plural.

Why?

• the preposition na can take different cases
• for location, it takes the locative
• leđa is plural in form
• so the result is na leđima

You may also notice that leđima is the same form as the instrumental plural. That is normal in Serbian: some plural endings are identical in different cases.

No, Serbian word order is fairly flexible, but the short words mi and je are clitics, so they follow special placement rules.

The neutral sentence is:

• Ranac mi je na leđima.

Other word orders are possible for emphasis or focus, for example:

• Na leđima mi je ranac. = emphasis on location
• Ranac je mi na leđima = not correct

The important thing is that clitics like mi and je usually appear in the second position area of the sentence or clause.

So an English speaker should not think of Serbian word order as completely free. It is flexible, but not random.

Yes, you can, and it would be understood. It means something like:

• I have a backpack on my back
• or simply I’m wearing/carrying a backpack on my back

But it is slightly different in structure and feel.

Compare:

• Ranac mi je na leđima. = a neutral statement about where the backpack is
• Imam ranac na leđima. = focuses more on I have/am carrying

Both are possible, but the original sentence is very natural when you are simply describing the situation.

Yes, that is grammatical.

It means:

• The backpack is on my back

But it sounds more explicit and slightly more marked than Ranac mi je na leđima.

Serbian often prefers:

• dative pronoun + body part noun rather than:
• possessive adjective + body part noun

So in everyday speech, Ranac mi je na leđima is usually more idiomatic.

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

So:

• ranac can mean a backpack, the backpack, or just backpack, depending on context.

In this sentence, context tells you which English article fits best.

This is very normal in Serbian, and learners have to get used to letting context do the job that articles do in English.

The letter đ is pronounced somewhat like the sound in British English duke or the j-like sound in during for some speakers, but softer and more distinctly Serbian.

So:

• leđima is approximately LEH-jyee-ma or LEH-djee-ma, depending on how you hear it explained

A rough breakdown:

• le = like le in let, but cleaner
• đi = soft dj
• ma = ma

You do not need a perfect English equivalent, because there is no exact one. The important thing is that đ is softer than dž.

A very literal breakdown is:

• Ranac = backpack
• mi = to me / my
• je = is
• na leđima = on the back

So the structure is roughly:

Backpack to-me is on back

That sounds strange in English, but it helps show how Serbian builds the sentence:

• subject first
• dative clitic for the person involved
• verb
• location phrase

A natural English translation is simply: My backpack is on my back.