Learn Hardcore Croatian: On je iskren i kaže što misli; međutim, ponekad mu ljudi ne vjeruju. - He is sincere and says what he thinks; however, sometimes people do not believe him.

iskren = sincere, frank, open, speaking honestly
- On je iskren. – He is sincere / He is frank.
- Emphasis: he says what he truly thinks and feels.
pošten = honest in the moral / ethical sense, fair, not cheating
- On je pošten. – He is honest (doesn’t steal, cheat, etc.).
- Emphasis: moral integrity, not being corrupt.

In the sentence On je iskren i kaže što misli, the idea is that he is open and sincere in his speech, so iskren is the natural choice.

Why is it kaže što misli and not kaže što on misli? Is on (he) omitted on purpose?

Croatian is a pro‑drop language: subject pronouns are often omitted when the subject is clear from the verb ending or context.

misli already tells us the subject is he/she/it (3rd person singular).
The context is already On je iskren (He is honest), so it is clear that misli refers to that same on.

So:

kaže što misli – perfectly natural and normal
kaže što on misli – also correct, but sounds more emphatic, like:
- he (as opposed to someone else) says what he thinks.

In neutral, everyday speech, kaže što misli is preferred.

What exactly does što mean in kaže što misli? Is it what or that?

In kaže što misli, što is a relative / interrogative pronoun meaning what. It introduces a clause as the object of the verb kaže:

kaže što misli
literally: he says what he thinks
(object of kaže = što misli)

It is not the same as that in English (as in he says that he thinks…). That construction would usually be:

kaže da misli... – he says that he thinks…

So here:

što = what
da (not used in this sentence) = that (for content / complement clauses).

Why is it što, not šta?

Both što and šta mean what and are widely understood.

što is considered more standard in Croatian (used in formal writing, news, education, etc.).
šta is very common in spoken language and in certain dialects/regions (especially in the south and in some urban speech).

In a textbook-style, standard sentence like this, što is expected:

On je iskren i kaže što misli. – standard.
On je iskren i kaže šta misli. – common in speech, less formal / more regional.

Why is there a semicolon before međutim? How is međutim used?

The sentence has:

On je iskren i kaže što misli; međutim, ponekad mu ljudi ne vjeruju.

The semicolon ();) is used because we have two closely related independent clauses that could each be a separate sentence:

On je iskren i kaže što misli.
Međutim, ponekad mu ljudi ne vjeruju.

Međutim means however / nevertheless. It introduces a contrast with what came before.

You can punctuate this in several acceptable ways:

On je iskren i kaže što misli. Međutim, ponekad mu ljudi ne vjeruju.
On je iskren i kaže što misli; međutim, ponekad mu ljudi ne vjeruju.
On je iskren i kaže što misli, međutim ponekad mu ljudi ne vjeruju. (less formal, some style guides dislike the comma here)

Functionally, međutim works much like English however at the start of a sentence or after a semicolon.

What is the difference between međutim and ali/no/nego?

All of these can express contrast, but usage differs:

ali = but (most common basic conjunction)
- On je iskren, ali mu ljudi ponekad ne vjeruju.
no = also but, often a bit more formal/literary
- On je iskren, no ljudi mu ponekad ne vjeruju.
međutim = however / nevertheless, usually at the beginning of a clause or sentence
- On je iskren i kaže što misli. Međutim, ponekad mu ljudi ne vjeruju.
nego = but rather / but instead, used after a negation to correct or replace something
- Ne mislim da je nepošten, nego da je previše iskren.
  (I don’t think he’s dishonest, but rather that he’s too honest.)

In your sentence, međutim is chosen to introduce a new sentence/clause that contrasts with the previous information, similar to English however.

Why is it ponekad mu ljudi ne vjeruju? Could it be Ljudi mu ponekad ne vjeruju? How strict is word order here?

Word order in Croatian is relatively flexible compared to English, but it affects emphasis and rhythm.

The given version:

ponekad mu ljudi ne vjeruju
- literally: sometimes to‑him people don’t believe
- starts with ponekad (sometimes), so the time/frequency is in focus.

Another perfectly correct option:

Ljudi mu ponekad ne vjeruju.
- starts with ljudi (people), so the subject is more in focus.

Both mean sometimes people don’t believe him. The core constraints:

The clitic mu normally appears in the second position in the clause:
- Ponekad mu ljudi ne vjeruju.
- Ljudi mu ponekad ne vjeruju.
- Ne vjeruju mu ponekad ljudi. (also possible, though less neutral)

So word order is flexible, but clitics like mu must be near the front (second position in the clause).

Why is mu in the dative case, and how does vjerovati work with objects?

mu is an unstressed (clitic) form of njemu = to him (3rd person singular, dative).

The verb vjerovati (to believe) usually works like this:

vjerovati + dative (person) = believe somebody, trust somebody
- Vjerujem mu. – I believe him.
- Ljudi mu ne vjeruju. – People don’t believe him.
vjerovati u + accusative (thing / concept) = believe in something/someone
- Vjerujem u Boga. – I believe in God.
- Vjeruje u pravdu. – He believes in justice.

In your sentence:

ponekad mu ljudi ne vjeruju
- mu = to him (dative)
- object of vjeruju in the sense believe him / trust him.

Why is it ne vjeruju (present tense)? Does it refer to a general habit or something happening now?

Present tense in Croatian (vjeruju) can express:

General truth / habit / repeated action
That is the meaning here:
- Ponekad mu ljudi ne vjeruju.
  = Sometimes people don’t believe him. (repeated / typical situation)
Action happening right now (equivalent to English present continuous in many contexts)
- Što rade? Vjeruju mu ili ne? – What are they doing? Do they believe him or not?

Here, with ponekad (sometimes), the natural interpretation is habitual / repeated, not just at this very moment.

Could we say On je iskren i govori što misli instead of kaže što misli? What is the difference between reći / kazati and govoriti?

Yes, you could say:

On je iskren i govori što misli.

The nuance:

reći / kazati (perfective; here form kaže) = to say, to tell (a specific act/utterance)
- kaže što misli = he says what he thinks (each time he speaks, he expresses his real thoughts).
govoriti (imperfective) = to speak, to talk, to say in general / habitually
- govori što misli = he speaks what he thinks; he generally talks in a way that reflects his real thoughts.

In this sentence, kaže što misli focuses a bit more on each act of speaking, but the difference is subtle; both are natural and idiomatic.

Why is the adjective iskren in the masculine form? How would it change with a different subject?

The form of iskren agrees with the subject on (he), which is masculine singular:

On je iskren. – He is honest (masc. sg.).

If the subject changed, the adjective would change to match:

Ona je iskrena. – She is honest. (feminine singular)
Ono je iskreno. – It is honest. (neuter singular)
Oni su iskreni. – They are honest. (masc. plural or mixed group)
One su iskrene. – They (females) are honest. (fem. plural)

So iskren → iskrena / iskreno / iskreni / iskrene, depending on gender and number of the subject.

Could we drop On and just say Iskren je i kaže što misli?

Yes. In Croatian, it is natural to omit subject pronouns when they are clear from context or from verb endings.

So you can say:

On je iskren i kaže što misli. – He is honest and says what he thinks.
Iskren je i kaže što misli. – (He) is honest and says what he thinks.

The second version is perfectly normal and often even more natural in continuous text, when it’s clear who you are talking about.

What does ljudi mean exactly, and what is its singular form?

ljudi means people (plural).

Its singular base word is čovjek = person / man (human being).

The relationship is irregular:

singular: čovjek – a person / a human being
plural: ljudi – people / humans

You don’t say čovjeci for the normal plural; ljudi is the standard plural form used in most contexts:

Ljudi mu ponekad ne vjeruju. – People sometimes don’t believe him.