Da nema toliko novih padeža, učila bih hrvatski što opuštenije i bez straha.

It is a hypothetical conditional sentence: it talks about an unreal or imagined situation and its result.

• Da nema toliko novih padeža = If there weren’t so many new cases
• učila bih hrvatski što opuštenije i bez straha = I would learn Croatian as relaxedly as possible and without fear

So this is the Croatian equivalent of an English If ..., I would ... sentence.

Here da nema means if there weren’t / if there were not.

Literally:

• da can introduce a hypothetical clause
• nema means there isn’t / there aren’t

But together in this kind of sentence, da + present tense often expresses an unreal condition:

• Da nema problema, bilo bi lakše.
  If there were no problems, it would be easier.

So in your sentence, da nema toliko novih padeža is not just a literal that there aren’t so many new cases. It functions as if there weren’t so many new cases.

Because Croatian usually uses ima / nema to express there is / there isn’t or there are / there aren’t.

So:

• ima vremena = there is time
• nema vremena = there is no time
• ima problema = there are problems
• nema problema = there are no problems

In this sentence, the meaning is existential: there aren’t so many new cases, so nema is the natural choice.

Using nije would mean is not, which is a different structure.

There are two reasons.

1. nema normally requires the genitive
   After existential nema, the thing that is absent usually goes in the genitive:

   • nema vode = there is no water
   • nema knjige = there is no book
   • nema padeža = there are no cases

2. toliko is also followed by the genitive
   Quantities like toliko (so many / so much) are followed by a genitive form:

   • toliko ljudi = so many people
   • toliko novih padeža = so many new cases

So:

• novih = genitive plural of novi
• padeža = genitive plural of padež

Padež means grammatical case.

Its plural is padeži = cases.

In the sentence, novih padeža means new grammatical cases. A learner might think of Croatian cases like nominative, genitive, dative, accusative, vocative, locative, and instrumental.

Učila bih is the conditional form, meaning I would learn.

It is made of:

• učila = the l-participle of učiti (to learn), feminine singular
• bih = the conditional auxiliary for I would

So:

• učila bih = I would learn said by a female speaker
• a male speaker would say učio bih

This form matches the hypothetical condition in the first half of the sentence.

Yes, both word orders can occur, but učila bih is very natural here.

Croatian clitics such as bih tend to appear in second position, but what counts as the first unit can vary. In many sentences, putting the participle first is normal:

• Učila bih hrvatski. = I would learn Croatian.

So the version in your sentence sounds completely normal.

Because the participle agrees with the speaker’s gender.

• učila bih = said by a female
• učio bih = said by a male

Croatian past participles and conditional forms often show gender in the singular.

So this sentence sounds as if the speaker is female. If the speaker were male, it would be:

Da nema toliko novih padeža, učio bih hrvatski što opuštenije i bez straha.

Yes. Učiti hrvatski means to learn Croatian.

Here hrvatski is understood as the Croatian language, with jezik omitted.

You can think of it as short for:

• učiti hrvatski jezik

But in normal speech, people very often just say:

• učiti hrvatski
• govoriti hrvatski

Grammatically, hrvatski is in the accusative singular, matching the omitted noun jezik.

It means as relaxed as possible or as casually/comfortably as possible.

This is a common Croatian pattern:

• što + comparative

Examples:

• što prije = as soon as possible
• što bolje = as well as possible
• što jednostavnije = as simply as possible

So:

• opuštenije = more relaxed
• što opuštenije = as relaxedly as possible

In natural English, you would usually say as relaxed as possible rather than as relaxedly as possible.

In this sentence it functions adverbially, because it describes how the speaker would learn Croatian.

It answers the question:

• How would I learn Croatian?
• Što opuštenije.

So even though the form looks like the comparative of the adjective opušten, here it works like an adverb in meaning: more relaxedly / in a more relaxed way.

Because the preposition bez means without, and bez requires the genitive.

So:

• strah = fear (nominative)
• bez straha = without fear (genitive)

This is a very common pattern:

• bez problema = without problems
• bez šećera = without sugar
• bez straha = without fear

I simply means and.

It links two expressions that describe the manner of learning:

• što opuštenije = as relaxed as possible
• bez straha = without fear

So together they mean something like:

as relaxed as possible and without fear

It sounds natural.

A Croatian speaker would understand it immediately, and the structure is normal:

• hypothetical clause with da nema
• conditional result with učila bih
• natural manner expressions like što opuštenije and bez straha

The only thing that makes it feel a bit like a learner-related sentence is the topic itself—so many new cases—because that is exactly the kind of thing language learners talk about. But grammatically and stylistically, it is fine.

Yes. Croatian has several ways to express a hypothetical condition. For example, you could also hear something like:

• Kad ne bi bilo toliko novih padeža, učila bih hrvatski...
• Da nije toliko novih padeža, učila bih hrvatski...

But Da nema toliko novih padeža... is perfectly good and very natural.

So for a learner, the important thing is:

• da + present can express a hypothetical condition
• the main clause then often uses the conditional, like učila bih