Ako imaš ikakvo pitanje, pitaj me odmah.

Ako means if.

So Ako imaš ikakvo pitanje, pitaj me odmah. literally follows the pattern:

• Ako ... = If ...
• ..., pitaj me odmah. = ..., ask me right away.

This is a very common way to make a conditional sentence in Croatian.

The comma separates the if-clause from the main clause.

• Ako imaš ikakvo pitanje = If you have any question
• pitaj me odmah = ask me immediately

In Croatian, when a subordinate clause comes first, it is normally separated by a comma.

Ikakvo means something like:

• any
• any at all
• some kind of

In this sentence, it gives the sense of if you have any question whatsoever.

Compare:

• Ako imaš pitanje... = If you have a question...
• Ako imaš neko pitanje... = If you have some question...
• Ako imaš ikakvo pitanje... = If you have any question at all...

So ikakvo adds a slightly stronger any whatsoever feeling.

It is in the accusative singular, because it is the direct object of imaš (you have).

The verb imati usually takes a direct object in the accusative:

• imaš pitanje = you have a question

For neuter singular nouns like pitanje, the nominative and accusative forms are the same:

• nominative: pitanje
• accusative: pitanje

The adjective has to agree with the noun, so:

• ikakvo pitanje

Both words match in gender, number, and case.

Imaš is the 2nd person singular present tense of imati (to have).

So:

• ja imam = I have
• ti imaš = you have
• on/ona/ono ima = he/she/it has

Because the sentence is speaking to one person informally, Croatian uses imaš.

It is informal singular.

You can tell because of:

• imaš = you have (informal singular)
• pitaj = ask (informal singular imperative)

If you were speaking to:

• one person formally, or
• more than one person,

you would use:

Ako imate ikakvo pitanje, pitajte me odmah.

So:

• imaš / pitaj = informal singular
• imate / pitajte = formal singular or plural

Pitaj is the imperative of pitati (to ask), for you singular informal.

It means:

• ask!

Examples:

• Pitaj me. = Ask me.
• Pitaj odmah. = Ask right away.

Related forms:

• pitaj = ask! (to one person, informal)
• pitajte = ask! (to more than one person, or formal)

In Croatian, short object pronouns like me often come in a fixed position, but with the imperative, verb + pronoun is very common and natural:

• pitaj me = ask me
• reci mi = tell me
• nazovi ga = call him

So pitaj me odmah is the normal wording here.

You may sometimes see different word order for emphasis in other contexts, but pitaj me is the standard form you should learn first.

Me means me.

It is the unstressed object pronoun for ja (I), used here as the direct object of pitaj:

• pitaj me = ask me

Some related pronouns:

• me = me
• te = you
• ga = him/it
• je = her/it
• nas = us
• vas = you (plural/formal)

Odmah means:

• immediately
• right away
• at once

So:

• pitaj me odmah = ask me immediately / right away

It adds urgency or encourages the listener not to wait.

Yes. Ako imaš bilo kakvo pitanje is also correct and very common.

Both are close in meaning:

• ikakvo pitanje = any question / any question at all
• bilo kakvo pitanje = any kind of question / whatever question you may have

In many situations they are almost interchangeable.
Bilo kakvo can sound slightly more explicit, like any kind whatsoever.

Yes, it could be plural, but the singular is very natural here.

Croatian often uses singular in places where English also uses singular with any:

• Ako imaš ikakvo pitanje... = If you have any question...

You could also say:

• Ako imaš ikakvih pitanja...

This plural/genitive version is also common and can sound a bit more like if you have any questions.

So both singular and plural-type expressions are possible, but the sentence you were given is completely natural.

A fairly literal breakdown is:

• Ako = if
• imaš = you have
• ikakvo = any / any at all
• pitanje = question
• pitaj = ask
• me = me
• odmah = immediately

So, word-for-word:

If you have any question, ask me immediately.

In more natural English, you would usually say:

If you have any questions, ask me right away.

It is the most normal and straightforward choice here.

The base verb is:

• pitati = to ask

You may also encounter related verbs such as:

• upitati = to ask

But in everyday speech, pitaj me is the most natural basic phrase to learn first.

So for a learner, the safest pattern is:

• Pitaj me. = Ask me.

Usually no. Croatian often leaves subject pronouns unstated when the verb already makes the subject clear.

So:

• imaš already tells you it means you have
• pitaj already tells you it means you, ask

That is why there is no separate ti in the sentence.

If you added ti, it would usually be for emphasis:

• Ako ti imaš ikakvo pitanje, pitaj me odmah.

But that is not the neutral default.