Za putovanje uzimam jedan par starih, ali udobnih tenisica.

Because za often means for when you are talking about a purpose or intended use.

• za putovanje = for the trip / for travelling
• za školu = for school
• za posao = for work

After za in this meaning, Croatian normally uses the accusative case.
That is why you get putovanje here.

Since putovanje is a neuter noun, its nominative and accusative singular look the same, so you do not see a visible change.

In Croatian, the present tense is often used for something you are doing now or have decided to do, especially in everyday speech.

So uzimam can mean:

• I take
• I’m taking
• I’m going to take

Here it sounds natural as I’m taking or I’m taking along.

The verb uzeti / uzimati is a verb pair:

• uzeti = perfective, to take once / complete the action
• uzimati = imperfective, to be taking / take habitually / focus on the process

uzimam is from the imperfective verb uzimati.

Yes, but in this sentence it has the sense of:

• I’m taking
• I’m bringing along
• I’m packing

So Za putovanje uzimam... means something like:

• For the trip, I’m taking...
• For travelling, I’m bringing...

It is slightly more natural in English to expand take in this kind of context.

Both are possible, but they are slightly different in feel.

• par tenisica = a pair of sneakers
• jedan par tenisica = one pair of sneakers

Adding jedan makes the quantity more explicit. It can sound a bit more deliberate, as if you are specifying that you are taking one pair, not two.

Croatian often uses jedan in places where English might simply use a/an, but here it still keeps a clear numerical sense too.

Because after par (pair), Croatian usually puts the following noun in the genitive plural.

So:

• par cipela = a pair of shoes
• par čarapa = a pair of socks
• par tenisica = a pair of sneakers

Here:

• tenisice = sneakers/trainers
• tenisica = genitive plural form

So jedan par starih, ali udobnih tenisica literally works like:

• one pair of old but comfortable sneakers

Because the adjectives agree with tenisica, and tenisica is in the genitive plural after par.

So the whole phrase is built like this:

• par tenisica = pair of sneakers
• par starih tenisica = pair of old sneakers
• par starih, ali udobnih tenisica = pair of old but comfortable sneakers

The adjectives must match the noun they describe:

• tenisica = feminine genitive plural
• therefore starih and udobnih are also feminine genitive plural forms

This is one of the things English speakers often notice: in Croatian, adjectives change form depending on case, number, and gender.

Because this is not the basic plural form; it is the genitive plural.

The basic dictionary form is:

• singular: tenisica
• plural: tenisice

But after par, you need genitive plural, which is:

• tenisica

So:

• Tenisice su nove. = The sneakers are new.
• Imam tenisice. = I have sneakers.
• Uzimam par tenisica. = I’m taking a pair of sneakers.

It may look strange because the genitive plural here happens to look like the singular nominative form.

Because ali means but, and in Croatian it normally introduces a contrast.

So:

• starih, ali udobnih tenisica = old, but comfortable sneakers

The comma marks that contrast clearly, just as in English:

• old, but comfortable

This punctuation is standard and natural.

Yes. Croatian word order is more flexible than English word order, although some versions sound more natural in certain contexts.

The given sentence:

• Za putovanje uzimam jedan par starih, ali udobnih tenisica.

puts za putovanje first for emphasis, like As for the trip... or For the trip...

Other possible orders include:

• Uzimam jedan par starih, ali udobnih tenisica za putovanje.
• Jedan par starih, ali udobnih tenisica uzimam za putovanje.

These all mean roughly the same thing, but the focus shifts slightly.

• Starting with Za putovanje highlights the purpose first.
• Starting with Uzimam is more neutral.
• Starting with Jedan par... emphasizes the item.

It can correspond to all three, depending on context.

• putovanje often means trip
• it can also mean journey
• in broader contexts, it can mean travelling

So za putovanje could be understood as:

• for the trip
• for the journey
• for travelling

In this sentence, any of those is possible, and the exact English choice depends on the translation style.

Yes, tenisice is a very common everyday word for sneakers or trainers.

Depending on region and speaker, you may also hear other terms, but tenisice is standard and widely understood.

So:

• stare tenisice = old sneakers
• udobne tenisice = comfortable sneakers

In this sentence, it is a very natural clothing/travel item.

It is in the accusative, but for this noun the nominative and accusative singular are the same.

The direct object of uzimam is:

• jedan par starih, ali udobnih tenisica

Here:

• par is masculine inanimate
• masculine inanimate nouns usually have the same form in nominative and accusative singular

So although the case is accusative, the form stays par.

That is why you do not see a visible change.

Yes, but that would change the structure.

• stare, ali udobne tenisice = old but comfortable sneakers
• par starih, ali udobnih tenisica = a pair of old but comfortable sneakers

If you remove par, then the noun phrase stands directly as the object, and the adjectives would change accordingly:

• Uzimam stare, ali udobne tenisice.

Here the adjectives agree with tenisice in the accusative plural, not the genitive plural.

So both are correct, but they are built differently.