Ako zaboravim odmrznuti povrće, večera će kasniti.

Because after ako (if), Croatian normally uses the present tense, even when the meaning is future.

So:

• Ako zaboravim... = If I forget...
• not Ako ću zaboraviti...

This is similar to English, where we also say If I forget, not If I will forget.

In Croatian, this is the normal pattern for real future conditions:

• Ako dođe, javit ću ti. = If he comes, I’ll let you know.
• Ako bude kiše, ostat ćemo doma. = If it rains / If there is rain, we’ll stay home.

This is because zaboraviti is a perfective verb. In Croatian, perfective verbs often use present-tense forms to refer to a single completed action in the future, especially in clauses like this.

So zaboravim literally looks like present tense, but in context it means:

• if I end up forgetting
• if I forget

Compare:

• zaboravljam = I am forgetting / I keep forgetting / I forget habitually
• zaboravim = I forget once, as a completed event

Here the speaker means one specific future mistake, so zaboravim is the natural choice.

Because after zaboraviti (to forget), Croatian commonly uses the infinitive to say what someone forgot to do.

So:

• zaboraviti odmrznuti povrće = to forget to defrost the vegetables

This works much like English forget to do.

Other examples:

• Zaboravio sam nazvati. = I forgot to call.
• Zaboravila je kupiti kruh. = She forgot to buy bread.

So odmrznuti is in the infinitive because it depends on zaboravim.

Odmrznuti means to defrost or to thaw.

It is built from the verb mrznuti / zamrznuti area of meaning connected with freezing, and od- gives the idea of reversing that state.

So:

• zamrznuti = to freeze
• odmrznuti = to unfreeze / defrost / thaw

In everyday kitchen language, odmrznuti povrće is exactly what you would say for taking frozen vegetables and letting them thaw before cooking.

In Croatian, povrće is usually a collective / mass noun, even though in English we often translate it as vegetables.

So povrće can mean:

• vegetables in general
• a quantity of vegetables
• mixed vegetables

That is why Croatian often uses singular agreement and a singular-looking noun where English prefers a plural idea.

Examples:

• Volim povrće. = I like vegetables.
• Kupio sam smrznuto povrće. = I bought frozen vegetables.

Yes, it is the direct object, so it is functioning as an accusative. But with povrće, the nominative and accusative forms are the same.

So:

• nominative: povrće
• accusative: povrće

This is common with many neuter nouns in Croatian: nominative and accusative singular are identical.

So even though the form does not change visibly, its role in the sentence is still accusative object.

Because the sentence begins with a subordinate if-clause:

• Ako zaboravim odmrznuti povrće, ...

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

So the structure is:

• Ako ... , ...
• If ... , ...

This is standard punctuation.

Croatian future tense is made with:

• the clitic će
• plus the infinitive

So the basic idea is:

• će kasniti = will be late

In a full sentence, Croatian clitics like će usually go in second position. That is why you get:

• Večera će kasniti.

Here večera comes first, and će comes right after it.

You may also see:

• Kasnit će večera.

That is also possible, but the emphasis and word order feel different.

So večera će kasniti is a very normal, neutral way to say dinner will be late.

It can mean both, depending on context.

In this sentence, večera će kasniti most naturally means:

• dinner will be late
• dinner will be delayed

Since večera is not a person, English often prefers be delayed, but be late is also perfectly understandable.

Other examples:

• Autobus kasni. = The bus is late.
• Ručak kasni. = Lunch is running late / Lunch is delayed.

You might hear something like that, but kasniti is the more natural choice here.

Why?

• kasniti = to be late / to run late / to be delayed
• zakasniti often emphasizes arriving too late or being late for something

For a meal being delayed, kasniti sounds more idiomatic:

• Večera kasni.
• Ručak kasni.

So the original sentence is the best everyday phrasing.

Because the thing that will be late is dinner.

In the second clause:

• večera = subject, nominative singular
• će kasniti = predicate, future tense

So the structure is literally:

• Dinner will be late.

Even though English learners may first focus on I forget, the main clause has its own subject: večera.

Yes, Croatian word order is flexible, although some versions sound more neutral than others.

The original:

• Ako zaboravim odmrznuti povrće, večera će kasniti.

Possible alternatives:

• Večera će kasniti ako zaboravim odmrznuti povrće.
• Ako zaboravim odmrznuti povrće, kasnit će večera.

These all make sense, but the original is very natural and neutral.

A good rule:

• put the if-clause first if you want to set up the condition first
• keep će in second position in its clause

It is a real, possible future condition.

The sentence means something like:

• If I forget to defrost the vegetables, dinner will be late.

This is not contrary-to-fact or imaginary in the way English might use If I forgot... dinner would be late.

Croatian marks this as a normal, realistic future condition by using:

• ako
  • present form
• future tense in the main clause

So it is the standard pattern for if X happens, Y will happen.