Moj brat je hrabriji od mene.

Because moj has to agree with the noun brat.

• brat means brother
• It is a masculine singular noun
• So the possessive adjective must also be masculine singular

That gives:

• moj brat = my brother

Compare:

• moj brat = my brother
• moja sestra = my sister
• moje dijete = my child

So the form of my changes depending on the gender and number of the noun.

Because Croatian does not use articles the way English does.

So:

• brat can mean a brother, the brother, or just brother, depending on context
• moj brat is naturally understood as my brother

English requires articles, but Croatian usually does not.

Je is the 3rd person singular form of the verb biti = to be.

So here:

• moj brat = my brother
• je = is
• hrabriji = braver
• od mene = than me / than I am

So je is simply the word is.

A useful note: in Croatian, short forms like je often appear in the second position in the sentence.

Hrabriji is the comparative form of hrabar = brave.

So:

• hrabar = brave
• hrabriji = braver

Croatian often forms comparatives by changing the adjective ending, and sometimes the stem changes a little too. This is why it is not hrabariji, but hrabriji.

Other examples:

• mlad = young → mlađi = younger
• star = old → stariji = older
• brz = fast → brži = faster

So hrabriji is just the normal comparative adjective meaning braver.

After a comparative adjective like hrabriji = braver, Croatian commonly uses od + genitive to mean than.

So:

• od = than / from, depending on context
• mene = me, in the form required after od

That is why you get:

• hrabriji od mene = braver than me

The important grammar point is that od requires the genitive case, and the pronoun ja changes form:

• ja = I
• mene = of me / than me / me after certain prepositions

Because ja is the nominative form, but after the preposition od, Croatian needs the genitive form.

For the pronoun I, some key forms are:

• ja = I
• mene = me / of me
• meni = to me
• mnom / mnome = with me

So in this sentence:

• od mene is correct
• od ja is incorrect

This is one of the biggest differences from English: Croatian changes pronoun forms much more systematically because of case.

Yes, sometimes Croatian can use nego in comparisons, especially in more clause-like comparisons.

For example:

• Moj brat je hrabriji od mene
• Moj brat je hrabriji nego ja

Both can be heard and understood as My brother is braver than me / than I am.

However, for learners, od + genitive is often the clearest and most reliable pattern to learn first with comparatives:

• veći od mene = bigger than me
• brži od njega = faster than him
• starija od tebe = older than you

So od mene is a very standard and useful structure.

Croatian word order is more flexible than English word order, but short unstressed words like je usually go in the second position.

So:

• Moj brat je hrabriji od mene is the normal order

The first unit is Moj brat, and then the clitic je comes early in the sentence.

English is more rigid:

• My brother is braver than me

Croatian allows more movement for emphasis, but the version you have is the neutral, natural one.

Yes, Croatian word order is fairly flexible, especially for emphasis or style.

For example, you may also see:

• Moj brat je hrabriji od mene
• Od mene je moj brat hrabriji
• Moj brat je od mene hrabriji

These do not all sound equally neutral in every context, but they are possible.

The version you were given is the most straightforward and natural for learners:

• Moj brat je hrabriji od mene

Yes, sometimes Croatian leaves out possessive words if the meaning is already clear from context.

So depending on the situation, a speaker might say simply:

• Brat je hrabriji od mene = Brother / my brother is braver than me

But moj brat is perfectly normal and clear, especially if you want to emphasize that you mean my brother.

So:

• moj brat = explicit, clear
• brat = often possible if context already tells whose brother it is

A simple learner-friendly approximation is:

• hra-bri-ji

You can think of it roughly like:

• HRAH-bree-yee

A few helpful points:

• h is pronounced
• r is clearly pronounced
• j sounds like English y in yes
• so ji sounds like yee

So hrabriji should not sound like English brijee all blended into one vague sound; each part is pronounced fairly clearly.

In meaning, yes, often it corresponds to English me, but grammatically it is more specific.

Croatian pronouns have different forms depending on case and whether they are stressed or unstressed.

For I / me, compare:

• ja = I
• me = me, short unstressed form
• mene = me, longer stressed form or form used after prepositions

Since od is a preposition, you need:

• od mene

not:

• od me

So mene is the correct form here because the grammar requires it.

Strictly speaking, it says that the brother is braver than the speaker. It is a comparison, not just a basic description.

So:

• Moj brat je hrabar = My brother is brave
• Moj brat je hrabriji od mene = My brother is braver than me

The second sentence suggests a comparison between two people:

• my brother
• me

It does not automatically say how brave either person is in absolute terms, only that the brother ranks higher in bravery.