Kad sjedimo kraj fontane, uvijek biramo stol dalje od prolaza, jer tamo ima manje buke.

Yes. Kad and kada both mean when.

• kada is the full form
• kad is the shorter, very common everyday form

In this sentence, Kad sjedimo kraj fontane... means When we sit / When we are sitting by the fountain...

Both are correct, but kad often sounds a bit more natural in casual speech.

This is about aspect, which is very important in Croatian.

• sjediti = to be sitting, to sit in a seated position, to sit regularly or for some time
• sjesti / sjednuti = to sit down, to take a seat

So:

• sjedimo means we sit or we are sitting
• sjednemo means we sit down

In this sentence, the idea is not the action of taking a seat, but the situation of being seated somewhere. That is why sjedimo is used.

After kraj meaning by, near, or next to, Croatian normally uses the genitive case.

So:

• fontana = fountain
• fontane = genitive singular of fontana

That is why you get:

• kraj fontane = by the fountain

This is a very common pattern:

• kraj kuće = by the house
• kraj ceste = by the road

Yes. All of these can mean by / beside / next to the fountain:

• kraj fontane
• pokraj fontane
• pored fontane

They are very similar in meaning. In many situations they are interchangeable.

A learner should mainly remember that all of them usually take the genitive:

• kraj fontane
• pokraj fontane
• pored fontane

Because stol is the direct object of biramo (we choose).

The noun stol is masculine inanimate, and for many masculine inanimate nouns, the accusative singular looks the same as the nominative singular.

So:

• nominative: stol
• accusative: stol

That is why biramo stol is correct.

Compare that with a masculine animate noun, where the accusative would usually change:

• vidim čovjeka = I see the man

But:

• vidim stol = I see the table

It means farther from the passage/walkway.

Breakdown:

• dalje = farther, further
• od = from, than
• prolaza = genitive of prolaz (passage, walkway, aisle)

So:

• stol dalje od prolaza = a table farther from the walkway

Here dalje is not changing to match stol. It is an adverb/comparative form meaning farther.

Because od requires the genitive case.

So:

• prolaz = passage, walkway
• prolaza = genitive singular

This happens very often in Croatian:

• od kuće = from the house
• od grada = from the city
• dalje od prolaza = farther from the walkway

Jer means because.

It introduces the reason:

• ...uvijek biramo stol dalje od prolaza, jer tamo ima manje buke.
• ...we always choose a table farther from the walkway, because there is less noise there.

It is one of the most common ways to say because in everyday Croatian.

Because Croatian often uses ima in an existential meaning: there is / there are.

So:

• tamo ima manje buke = there is less noise there

Here ima does not literally mean has in the usual possession sense. It works more like:

• ima ljudi = there are people
• ima vremena = there is time
• tamo ima manje buke = there is less noise there

Using je would not sound natural for this idea.

Because manje here means less, as a quantity word, and after it Croatian commonly uses the genitive.

So:

• buka = noise
• buke = genitive singular
• manje buke = less noise

This is similar to:

• puno vode = a lot of water
• malo vremena = little time
• manje buke = less noise

If you said manja buka, that would mean smaller/lower noise as an adjective + noun phrase, which is not the normal way to express less noise here.

Uvijek means always.

In this sentence:

• uvijek biramo = we always choose

Croatian word order is fairly flexible, so uvijek can sometimes move, but some positions sound more natural than others.

The original version is very natural:

• Kad sjedimo kraj fontane, uvijek biramo stol...

You may also hear:

• Kad sjedimo kraj fontane, biramo uvijek stol...

But that sounds less natural in many contexts. For a learner, keeping uvijek before the verb is a good habit.

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

So:

• fontane can mean the fountain or just a fountain, depending on context
• stol can mean a table or the table

Croatian relies on context, word order, and sometimes other words to show whether something is specific or general.

That is why:

• biramo stol can naturally mean we choose a table without any separate word for a.

Because the sentence contains clauses that Croatian normally separates with commas.

1. Kad sjedimo kraj fontane is a dependent clause introduced by kad
2. jer tamo ima manje buke is another dependent clause introduced by jer

So commas help mark the structure:

• Kad sjedimo kraj fontane, ...
• ..., jer tamo ima manje buke.

This is standard Croatian punctuation.

Croatian word order is more flexible than English, but not completely free.

The original sentence is very natural:

• Kad sjedimo kraj fontane, uvijek biramo stol dalje od prolaza, jer tamo ima manje buke.

Some parts could move for emphasis, for example:

• Kad sjedimo kraj fontane, biramo uvijek stol dalje od prolaza...
• Tamo ima manje buke, pa uvijek biramo stol dalje od prolaza.

But not every rearrangement sounds equally natural. For learners, the original order is a very good model because it is clear and idiomatic.