Ako zijevaš cijelo jutro, možda ti ni kava ni hladna voda neće pomoći.

Because Croatian normally uses the present tense after ako when talking about a real or possible condition.

So Ako zijevaš... is the normal way to say If you are yawning... / If you keep yawning...

This is similar to English, where we also usually say If you feel tired, ..., not If you will feel tired, ...

Also, Croatian present tense often covers both simple present and progressive meanings, so zijevaš can mean both you yawn and you are yawning, depending on context.

Cijelo jutro is in the accusative and expresses duration of time: for the whole morning / all morning.

The noun jutro is neuter singular, so the adjective must agree with it:

• nominative: cijelo jutro
• accusative: cijelo jutro

Because jutro is neuter, the adjective is cijelo, not cijeli.

This is a very common Croatian pattern:

• cijeli dan = all day
• cijelu noć = all night
• cijelo jutro = all morning

Ti is the short dative form of you, so here it means to you.

It appears because pomoći takes the dative case in Croatian:

• pomoći komu? = to help whom?

So:

• ti pomoći = help you
• mu pomoći = help him
• nam pomoći = help us

That is why Croatian uses ti, not te.
Te would be accusative, but pomoći does not take an accusative object here.

Because ti is a clitic, a short unstressed word. In Croatian, clitics usually go near the beginning of the clause, often in the second position.

So in: možda ti ni kava ni hladna voda neće pomoći

the clitic ti naturally comes right after možda.

This kind of placement is very typical in Croatian. English speakers often expect a more fixed order, but Croatian short pronouns often move into this early clitic position.

Ni ... ni ... means neither ... nor ...

So:

• ni kava ni hladna voda = neither coffee nor cold water

It is the normal Croatian structure for linking two negative alternatives.

Compare:

• i ... i ... = both ... and ...
• ni ... ni ... = neither ... nor ...

Because Croatian normally uses negative agreement here.

With ni ... ni ..., the verb is usually negative too, so the natural Croatian pattern is:

• Ni kava ni hladna voda neće pomoći.

This is different from English in form, but very normal in Croatian.
A positive verb here would sound unnatural.

Neće pomoći is the future tense:

• neće = will not
• pomoći = infinitive to help

So literally it is will not help.

The future is used because the main clause gives the expected result of the condition:

• Ako zijevaš cijelo jutro... = if that condition is true
• ... možda ti ... neće pomoći = then maybe it will not help you

This is the standard pattern:

• condition in the present after ako
• result in the future

This is a question of aspect.

• pomoći is perfective
• pomagati is imperfective

Here Croatian uses pomoći because the idea is about a result: whether coffee or cold water will actually help or not.

Perfective pomoći fits that completed-result meaning:

• neće pomoći = it will not help

If you used pomagati, it would suggest ongoing or repeated helping, which is not the most natural choice in this sentence.

Because Croatian has no articles like a, an, or the.

So kava can mean:

• coffee
• a coffee
• the coffee

And hladna voda can mean:

• cold water
• the cold water

The exact meaning depends on context, not on an article.

That is one of the big differences between English and Croatian.

Yes. Croatian word order is more flexible than English word order.

For example, you could also say:

• Ako cijelo jutro zijevaš, možda ti ni hladna voda ni kava neće pomoći.

The core meaning stays the same, but the emphasis changes slightly.

The original sentence sounds natural and neutral. Croatian often moves words around for rhythm, focus, or style, especially when clitics such as ti are involved.

Možda means maybe / perhaps.

It makes the statement less absolute:

• ... neće pomoći = ... will not help
• ... možda neće pomoći = ... maybe will not help

So the speaker is not presenting it as a certain fact, but as a possibility.

That makes the sentence sound more cautious and natural in many everyday contexts.