Često pretpostavljamo da će sve ići glatko, a onda se ipak događaju male komplikacije.

Because pretpostavljamo is 1st person plural present tense of pretpostavljati = to assume / to suppose.

So it means we assume.

A quick breakdown:

• pretpostavljam = I assume
• pretpostavljaš = you assume
• pretpostavlja = he/she/it assumes
• pretpostavljamo = we assume

In this sentence, the speaker is talking generally about us / people in general, so we assume fits naturally.

Često means often.

It is an adverb of frequency, and putting it near the beginning is very natural in Croatian. It sets the tone right away:

• Često pretpostavljamo... = We often assume...

Croatian word order is more flexible than English word order, so često could appear elsewhere too, but sentence-initial position is very common and sounds natural.

After verbs like pretpostavljati (to assume), misliti (to think), znati (to know), Croatian often introduces a subordinate clause with da = that.

So:

• pretpostavljamo da... = we assume that...

Then the clause itself is in the future:

• će ići = will go

So:

• pretpostavljamo da će sve ići glatko = we assume that everything will go smoothly

This is a very standard structure in Croatian.

Because će is the future-tense auxiliary. Croatian future I is usually made with:

• a form of htjeti in its short/clitic form
• plus the infinitive

So:

• ići = to go
• će ići = will go

In this sentence:

• da će sve ići glatko = that everything will go smoothly

The auxiliary će marks the future clearly.

Sve here means everything.

This is a pronoun, not just an adjective. In this meaning, sve is the correct form.

Compare:

• sve = everything
• svi = all people / all masculine plural
• sva = all things in some other grammatical contexts, or neuter plural adjective forms depending on structure

In this sentence, sve is the natural word for everything:

• da će sve ići glatko = that everything will go smoothly

Yes, ići literally means to go, but Croatian uses it in expressions just like English does.

So:

• sve ide glatko = everything goes smoothly
• sve će ići glatko = everything will go smoothly

This is very similar to English things are going well / everything will go smoothly. So although the basic meaning is to go, it is part of a common idiomatic expression.

Glatko literally means smoothly in this sentence.

It comes from gladak = smooth, and here it functions as an adverb:

• glatko = smoothly

So:

• ići glatko = to go smoothly

This is a very common collocation in Croatian.

A onda means and then / but then, depending on context.

Here it introduces a contrast between expectation and reality:

• Često pretpostavljamo da će sve ići glatko
  = We often assume everything will go smoothly,
• a onda...
  = and then / but then...

The a here is not just a simple and. It often has a mild contrastive feel, something like:

• and then
• but then
• whereas then

So it helps pivot the sentence from the assumption to what actually happens.

Ipak means something like:

• nevertheless
• still
• after all
• even so

In this sentence, it adds the idea that despite the expectation that things will go smoothly, complications still happen.

So:

• a onda se ipak događaju male komplikacije = but then small complications still happen / nevertheless small complications occur

It gives the sentence a more natural contrastive nuance. Without ipak, the sentence would still work, but it would lose some of that despite that expectation feeling.

Yes, the verb is događati se = to happen / to occur.

The se is part of the verb. In English, we do not say something happens itself, but in Croatian many verbs include se as part of their normal form.

So:

• događati se = to be happening / to happen repeatedly
• dogoditi se = to happen (completed event)

Here the sentence uses događaju se because it is talking about something that happens as a general pattern:

• male komplikacije se događaju = small complications happen

So yes, it is formally a se-verb, but you should learn događati se as a whole vocabulary item.

Because the subject is male komplikacije = small complications, which is plural.

So the verb must also be plural:

• komplikacija se događa = a complication happens
• komplikacije se događaju = complications happen

That is why you get događaju rather than singular događa.

Male komplikacije is in the nominative plural, because it is the subject of the verb događaju se.

Breakdown:

• mala komplikacija = a small complication
• male komplikacije = small complications

Here:

• komplikacije is feminine plural nominative
• male agrees with it in gender, number, and case

So the adjective and noun match:

• male komplikacije = small complications

Because Croatian often uses the present tense for:

• general truths
• habits
• repeated situations
• typical patterns

So:

• Često pretpostavljamo... = We often assume...
• događaju se... = ...complications happen

These are not necessarily happening only right now. They describe what usually happens.

This is very similar to English:

• We often assume...
• Then complications happen.

Good question. The sentence uses događaju se from događati se, which is the imperfective verb. That suggests:

• repeated occurrence
• general tendency
• ongoing pattern

This fits the sentence well, because it describes something that often happens in life.

If you used dogode se from dogoditi se (perfective), it would sound more like:

• specific completed events
• individual occurrences

So:

• događaju se male komplikacije = small complications happen / tend to occur
• dogode se male komplikacije = small complications occur / end up happening

Both can be possible in some contexts, but događaju se fits the habitual, general meaning especially well.

Croatian word order is flexible, but short unstressed words like se and će tend to follow special placement rules. They usually appear near the beginning of their clause, often in second position.

That is why you often see structures like:

• onda se ipak događaju...
• da će sve ići...

Also, Croatian word order is often arranged for emphasis and flow, not only grammar.

Other orders may be possible, for example:

• a onda se događaju ipak male komplikacije
• a onda male komplikacije ipak događaju se

But these sound less neutral or less natural. The original sentence has a very natural standard flow.

That would change the aspect and meaning.

• pretpostavljamo is imperfective: we assume, we tend to assume, we are assuming
• pretpostavimo is perfective and often sounds like a single completed assumption, or appears in other constructions

In a sentence about a repeated human tendency, pretpostavljamo is the natural choice:

• Često pretpostavljamo... = We often assume...

Using pretpostavimo with često would generally sound much less natural here.

It is very natural and usable in everyday Croatian, especially in speech or writing where you want to sound a bit thoughtful or explanatory.

The vocabulary is standard and common:

• često
• pretpostavljamo
• ići glatko
• ipak
• događaju se
• komplikacije

So this is not overly literary or stiff. It sounds like something a native speaker could easily say in conversation, in an article, in a presentation, or in advice-giving contexts.