Prodavnica je mala, ali je ispred nje veliki red.

Because the sentence has two separate clauses, and each one needs its own form of to be:

• Prodavnica je mala = The store is small
• ali je ispred nje veliki red = but there is a big line in front of it

So the two je forms are not redundant; each belongs to a different part of the sentence.

This is because je is a clitic in Serbian, meaning it is a short unstressed word that usually likes to stand near the beginning of the clause, often in second position.

So ali je ispred nje veliki red is natural Serbian word order.

You may also hear:

• Ali ispred nje je veliki red.

That is also possible and natural. Serbian word order is more flexible than English, but clitics like je have their own placement rules.

Ispred nje means in front of it / in front of her, depending on context.

Here it means in front of the store.

Breakdown:

• ispred = in front of
• nje = her / it in the form required after this preposition

Since prodavnica is a feminine noun, Serbian refers back to it with the feminine pronoun form.

Because after the preposition ispred, Serbian uses the genitive case, and the pronoun must match that case.

For ona (she/it, feminine), the relevant form here is nje.

So:

• ispred nje = in front of her/it

You cannot use ju or joj here, because those belong to different grammatical roles/cases.

Also, after prepositions, Serbian often uses the full stressed pronoun forms, not the short clitic ones.

Because prodavnica is a feminine singular noun, and adjectives must agree with the noun in gender, number, and case.

So:

• prodavnica = feminine singular
• mala = feminine singular form of small

Compare:

• mala prodavnica = small store
• mali red would not fit here, because red is masculine, not feminine

Because red is a masculine singular noun, so the adjective must also be masculine singular:

• veliki = masculine singular
• red = masculine singular

So:

• veliki red = a big line / a long queue

This is the same agreement rule as with mala prodavnica, just with a different noun gender.

Yes, red can mean several things in Serbian, including:

• order
• row
• turn
• line / queue

In this sentence, because we are talking about a store and something being in front of it, red clearly means a line / queue of people.

So veliki red here means a big line or more naturally in English, a long line.

Yes. Serbian often expresses there is / there are simply with a form of to be plus the noun phrase, without a special word like English there.

So:

• je ... veliki red literally uses is
• but the natural English translation is there is a big line

That is why ali je ispred nje veliki red is best understood as:

• but there is a big line in front of it

Because Serbian has no articles.

English distinguishes between:

• a store
• the store

Serbian usually leaves that unspecified unless context makes it clear, or unless another word is added.

So:

• Prodavnica can mean a store or the store
• veliki red can mean a big line or the big line, depending on context

Here, English normally translates it as The store is small, but there is a big line in front of it.

Yes, that is also a correct and natural sentence.

Both of these are possible:

• Prodavnica je mala, ali je ispred nje veliki red.
• Prodavnica je mala, ali ispred nje je veliki red.

The difference is mainly word order and emphasis, not basic meaning.

The version with je immediately after ali reflects the common tendency for clitics to appear early in the clause.

No. Prodavnica is a very common everyday word for store/shop, but Serbian also has other words depending on context, such as:

• radnja = shop, business
• dućan = shop, a bit more regional or colloquial in some areas
• trgovina = store/shop, sometimes more formal or broad

In this sentence, prodavnica is a perfectly normal and common choice.