Learn Hardcore Croatian: Iskreno, hrvatski je ponekad težak.

Iskreno literally comes from the adjective iskren (honest, sincere) and is the neuter singular form used adverbially, meaning honestly, frankly, to be honest.

In this sentence, Iskreno is a sentence adverb or discourse marker. It doesn’t describe how Croatian is difficult; it comments on the whole statement, signalling the speaker’s attitude: “To be honest, Croatian is sometimes hard.”

Why is there a comma after Iskreno?

The comma separates an introductory element from the rest of the sentence.

Iskreno is functioning like English Honestly, or Frankly, which almost always take a comma when they appear at the start of a sentence.

So:

Iskreno, hrvatski je ponekad težak. = Honestly, Croatian is sometimes hard.

Without a comma it looks odd and less standard in writing, though in casual online writing some people might skip it.

Why is it just hrvatski and not hrvatski jezik?

In Croatian, names of languages are usually expressed with an adjective like hrvatski (Croatian), engleski (English), njemački (German), etc.

Very often, the noun jezik (language) is simply understood and omitted:

hrvatski (jezik) = Croatian (language)
učim hrvatski = I’m learning Croatian (language)

So Iskreno, hrvatski je ponekad težak. really means:

Honestly, the Croatian language is sometimes difficult,
but jezik is left out because it’s obvious from context.

Why is hrvatski not capitalized like Croatian in English?

In Croatian, adjectives derived from country or nationality names are not capitalized:

hrvatski jezik (Croatian language)
engleska književnost (English literature)
njemački profesor (German teacher)

You only capitalize proper nouns like:

Hrvatska (Croatia)
Engleska (England)
Njemačka (Germany)

Since hrvatski here is an adjective (meaning “Croatian”), it stays lowercase.

Why does je come right after hrvatski? Could I start the sentence with je?

You can’t start a normal statement with je in Croatian.

Je is a clitic form of the verb biti (to be). Croatian clitics typically go in second position in the sentence (or in the clause).

In Iskreno, hrvatski je ponekad težak. the structure is:

Iskreno, – introductory word (outside the main clause)
hrvatski – first element of the main clause
je – clitic verb in second position of the clause
ponekad težak – the rest

So for the main clause, hrvatski is first, je is second.
Starting with je (e.g. Je hrvatski ponekad težak.) would sound ungrammatical.

Why is ponekad placed between je and težak? Could it go somewhere else?

Ponekad means sometimes and is an adverb of frequency. In Croatian, its position is flexible, but it cannot come before the clitic je in this sentence.

All of these are correct:

Iskreno, hrvatski je ponekad težak.
Iskreno, ponekad je hrvatski težak.
Hrvatski je ponekad težak.
Ponekad je hrvatski težak.

This one is unnatural or wrong:

✗ Hrvatski ponekad je težak. (splits hrvatski from je and breaks the clitic rule)

So: you can move ponekad around for emphasis, but je stays in that “second” slot of the clause.

Why is it težak and not teško?

Težak is an adjective meaning hard / difficult that agrees with the subject:

hrvatski (jezik) is masculine singular → težak (masculine singular form)

So:

hrvatski je težak = Croatian (language) is difficult.

Teško is the neuter or adverbial form and would usually mean hard in an adverbial sense:

Učiti hrvatski je teško. = Learning Croatian is hard.
(Here teško describes how it is to learn, not directly describing “Croatian”)

In your sentence you need an adjective agreeing with the implied noun jezik → težak.

Can I drop Iskreno and just say Hrvatski je ponekad težak?

Yes.

Hrvatski je ponekad težak. = Croatian is sometimes hard.

Adding Iskreno, adds a nuance: you’re making a slightly personal, candid statement:

Iskreno, hrvatski je ponekad težak. = To be honest, Croatian is sometimes hard.

Both are correct; the second one feels more like an admission or a confession.

Is there a difference between Iskreno, Iskreno rečeno, and Iskreno govoreći?

All three can introduce a sentence with a similar meaning (honestly, frankly), but there are small nuances:

Iskreno, – very common, short, conversational.
Iskreno rečeno, – literally honestly said; a bit more formal or “phrase-like”.
Iskreno govoreći, – literally speaking honestly; feels slightly more elaborate or bookish.

All can be followed by a comma and then your statement:

Iskreno, hrvatski je ponekad težak.
Iskreno rečeno, hrvatski je ponekad težak.
Iskreno govoreći, hrvatski je ponekad težak.

Could I say Iskreno, hrvatski je težak ponekad instead?

You can, and people will understand you, but it’s less natural.

Croatian normally puts frequency adverbs like ponekad closer to the verb or before the adjective in this kind of sentence:

hrvatski je ponekad težak – more natural
than
hrvatski je težak ponekad – possible, but sounds marked / slightly awkward

The version in your original sentence is the most typical word order.

Why do we need je at all? In some languages, “to be” can be omitted.

In standard Croatian, in a simple present tense sentence like this, you normally must include the verb biti (to be) in forms like sam, si, je, smo, ste, su:

Hrvatski je težak. (correct)
✗ Hrvatski težak. (incorrect as a full, neutral sentence)

You can omit je only in special contexts, for example in headlines, notes, or very casual fragments:

Hrvatski težak za početnike (headline style: Croatian (is) hard for beginners)

But in regular, complete sentences, je is required.

How do you pronounce hrvatski, especially the hrv cluster?

Hrvatski is pronounced roughly:

hr – a voiceless h followed immediately by a rolled or tapped r
vat – like “vaht” (short a)
ski – like “skee”

In IPA: [xř̩ʋatski] (approximation)

Tips for an English speaker:

Start with a light h (as in house), then immediately roll or tap your r.
Don’t add a vowel between h and r; avoid saying “huh-rvatski”. Try to go directly from h to r.
All vowels are short and clear; stress is usually on the first syllable: HR-vat-ski.