Kad ručamo s bakom nedjeljom, uvijek ostanemo za stolom malo dulje.

Yes. In this sentence, kad can be understood as when or whenever, because the whole sentence describes a repeated habit.

• Kad ručamo s bakom nedjeljom... = When/Whenever we have lunch with grandma on Sundays...

Because the main clause also has uvijek (always), the repeated meaning is especially clear.

Also, kad is a very common shorter form of kada. Both mean when.

Croatian often uses the present tense for habitual actions, just as English does in sentences like When we eat with grandma, we stay longer.

Here ručamo is the 1st person plural present of ručati:

• ja ručam = I have lunch
• mi ručamo = we have lunch

So Kad ručamo... literally means When we have lunch..., but in context it means a repeated event: Whenever we have lunch...

Because the preposition s (with) takes the instrumental case.

The noun baka changes in the instrumental singular:

• nominative: baka
• accusative: baku
• instrumental: bakom

So:

• s bakom = with grandma

This is a very common pattern in Croatian:

• s prijateljem = with a friend
• s mamom = with mum
• s bakom = with grandma

This is a very important distinction.

• nedjeljom = on Sundays, meaning habitually / every Sunday / on Sundays in general
• u nedjelju = on Sunday, meaning one specific Sunday or this coming Sunday, depending on context

So in your sentence:

• Kad ručamo s bakom nedjeljom... = When we have lunch with grandma on Sundays...

The form nedjeljom is the instrumental used adverbially for recurring time expressions. Croatian does this a lot with days of the week:

• ponedjeljkom = on Mondays
• utorkom = on Tuesdays
• subotom = on Saturdays
• nedjeljom = on Sundays

This is about aspect, which is one of the biggest things English speakers notice in Croatian.

• ostati = perfective
• ostajati = imperfective

Here ostanemo is the present form of the perfective verb ostati. In this kind of sentence, it suggests the action happens as a complete event each time: we end up staying a bit longer.

So:

• uvijek ostanemo malo dulje = we always stay a little longer / we always end up staying a little longer

If you said ostajemo, that would sound more like focusing on the ongoing situation or habit itself. It is not impossible in some contexts, but ostanemo is very natural here because it presents the staying-longer as what happens each time after lunch.

Because za stolom is the normal way to say at the table in the sense of being seated there.

Here the preposition za takes the instrumental because it expresses location, not movement.

Compare:

• sjesti za stol = to sit down at the table
  (za

  • accusative, movement toward the table)

• biti za stolom = to be at the table
  (za

  • instrumental, location)

• ostati za stolom = to remain at the table
  (za

  • instrumental, location)

So in your sentence:

• ostanemo za stolom = we stay/remain at the table

Na stolu means on the table, literally on top of it, so that would be completely different.

It means a little longer.

• malo = a little
• dulje = longer

Dulje is the comparative form related to dugo (long, for a long time).

So:

• ostanemo malo dulje = we stay a little longer

The idea is longer than usual or longer than expected.

You may also come across duže. That is also common, but dulje is very normal and often preferred in standard Croatian.

Because Kad ručamo s bakom nedjeljom is a subordinate clause placed before the main clause.

So the structure is:

• Kad ručamo s bakom nedjeljom, = subordinate time clause
• uvijek ostanemo za stolom malo dulje. = main clause

This is similar to English:

• When we have lunch with grandma on Sundays, we always stay at the table a little longer.

If the main clause came first, the comma rules could look different depending on style, but with the kad-clause first, the comma is expected.

Yes. Croatian word order is more flexible than English word order.

This sentence is natural as written:

• Kad ručamo s bakom nedjeljom, uvijek ostanemo za stolom malo dulje.

But some elements could move for emphasis or style, for example:

• Nedjeljom, kad ručamo s bakom, uvijek ostanemo za stolom malo dulje.
• Kad ručamo s bakom nedjeljom, ostanemo uvijek za stolom malo dulje.
• Kad ručamo s bakom nedjeljom, uvijek malo dulje ostanemo za stolom.

Not all versions sound equally neutral, but they are understandable. The original sentence sounds very natural and balanced.

Because Croatian does not have articles like a and the.

So stol can mean:

• a table
• the table

The exact meaning depends on context.

In this sentence, za stolom is naturally understood as at the table, because the situation is already clear.

This is normal in Croatian:

• Vidim psa. = I see the dog / a dog
• Sjedimo za stolom. = We are sitting at the table

Yes. Kad and kada both mean when.

• Kad ručamo s bakom nedjeljom...
• Kada ručamo s bakom nedjeljom...

Both are correct.

The difference is mainly stylistic:

• kad is shorter and very common in everyday speech
• kada can sound a bit fuller or slightly more formal, depending on context

In this sentence, kad sounds completely natural.

Because that is a very natural place for adverbs like uvijek (always) in Croatian.

• uvijek ostanemo = we always stay

Croatian allows some flexibility, but uvijek often goes before the verb it modifies. Putting it there makes the sentence sound neutral and fluent.

So:

• uvijek ostanemo za stolom malo dulje = the standard, natural version

If you move uvijek, the sentence may still be grammatical, but the rhythm or emphasis changes.