Ako nema ljepila, možeš uzeti selotejp; i on dobro drži papir.

Because after nema in the sense of there is no / there isn’t any, Croatian normally uses the genitive case.

• ljepilo = glue, nominative
• ljepila = genitive

So nema ljepila means there is no glue or there isn’t any glue.

This is a very common pattern:

• Ima kruha. = There is bread.
• Nema kruha. = There is no bread.

Most naturally, it means If there is no glue or If there isn’t any glue available.

There is no stated subject here, so it is understood in a general, impersonal way. In context, it is about the situation, not about one specific person.

So a learner should usually read it as:

• Ako nema ljepila = If there is no glue

Here možeš is basically giving an option or suggestion:

• možeš uzeti = you can take / you can use

It is not only literal ability. It can also mean:

• you may
• you could
• you have the option to

So the tone is practical and helpful: if glue is unavailable, tape is a possible alternative.

This is about aspect.

• uzeti is perfective: to take, as one complete action
• uzimati is imperfective: to be taking, to take repeatedly, habitually, or in an ongoing sense

In this sentence, the speaker means one complete action: take some tape instead. That is why uzeti is the natural choice.

With možeš, perfective infinitives are very common when giving practical suggestions:

• možeš kupiti
• možeš uzeti
• možeš posuditi

Yes. Selotejp is a common word for sticky tape / adhesive tape, originally based on the brand name Sellotape.

In Croatian it behaves like a regular masculine inanimate noun.

In this sentence:

• uzeti selotejp = to take some tape

Because it is masculine inanimate, its accusative singular is the same as its nominative singular:

• nominative: selotejp
• accusative: selotejp

You may also hear more descriptive expressions such as ljepljiva traka, but selotejp is very common in everyday speech.

Croatian pronouns follow grammatical gender.

Since selotejp is masculine, the pronoun referring back to it is on.

So:

• selotejp → on

Even though on also means he, it can refer to a masculine inanimate thing as well. English uses it, but Croatian uses gendered pronouns for objects too.

Compare:

• stol = table → on
• knjiga = book → ona
• pismo = letter → ono

Here i can be understood as and or also, but in this sentence it feels especially close to also / too.

So i on dobro drži papir is like saying:

• and it also holds paper well
• it works well for paper too

Without i, the sentence would still be grammatical:

• On dobro drži papir.

But i adds the idea of an extra useful point.

Here papir is in the accusative, because it is the direct object of drži.

It looks unchanged because masculine inanimate nouns often have the same form in the nominative and accusative singular.

So:

• nominative: papir
• accusative: papir

This is normal.

Compare with a masculine animate noun, where the accusative usually changes:

• nominative: student
• accusative: studenta

Literally, it means holds paper well.

But with glue, tape, nails, screws, and similar things, držati often means:

• to hold firmly
• to stick well
• to keep something attached

So here dobro drži papir means something like:

• it sticks well to paper
• it holds paper well
• it keeps paper together well

A natural English interpretation depends on context, but the basic idea is that the tape works effectively on paper.

Not completely. Croatian word order is fairly flexible, but the sentence as given sounds natural and neutral.

• Ako nema ljepila, možeš uzeti selotejp = straightforward advice
• i on dobro drži papir = natural continuation

You can move words for emphasis, but the focus changes a little. For example:

• Ako nema ljepila, selotejp možeš uzeti.
• I papir on dobro drži.

Those are possible, but the original is the most neutral and learner-friendly version.

The semicolon is just a punctuation choice. It links two closely related clauses while making a stronger break than a comma.

So the writer is separating:

• Ako nema ljepila, možeš uzeti selotejp
• i on dobro drži papir

A full stop would also be possible:

• Ako nema ljepila, možeš uzeti selotejp. On dobro drži papir.

The semicolon does not change the grammar; it mainly affects the rhythm and style.

The lj in Croatian is treated as a single sound. It is not just a plain l plus j said separately.

For English speakers, it can sound a bit like the lli in million, though it is not exactly the same.

A rough pronunciation guide:

• ljepila ≈ LYE-pee-la
• selotejp ≈ se-lo-teyp

The stress and exact sounds depend on accent, but that approximation is good enough for a learner starting out.