Ne mogu podnijeti visoku mjesečnu naknadu.

In Croatian, ne is written separately from most verbs, so ne mogu is correct.

• mogu = I can
• ne mogu = I cannot / I can’t

This is a very common beginner point. Croatian usually keeps the negative particle ne separate:

• ne znam = I don’t know
• ne želim = I don’t want
• ne mogu = I can’t

A few verbs are exceptions in standard Croatian, such as:

• nemam = I don’t have
• nisam = I am not

But mogu is not one of those exceptions.

Because after the modal verb mogu (can), Croatian normally uses the infinitive.

So the structure is:

• ne mogu = I can’t
• podnijeti = to endure / to bear / to tolerate

Together:

• Ne mogu podnijeti = I can’t bear / I can’t endure

This is very similar to English:

• I can’t sleep
• I can’t understand
• I can’t bear it

Croatian does the same kind of thing with modal verbs:

• Mogu doći. = I can come.
• Ne mogu čekati. = I can’t wait.
• Ne mogu podnijeti... = I can’t stand / bear...

Here podnijeti means to bear, to endure, to tolerate, or to stand.

So Ne mogu podnijeti visoku mjesečnu naknadu means something like:

• I can’t bear the high monthly fee
• I can’t stand the high monthly charge
• I can’t handle the high monthly fee

Depending on context, it can suggest either:

1. emotional tolerance: the fee is too much to accept, or
2. practical/financial burden: the fee is too heavy to manage

A useful related pair is:

• podnijeti = perfective
• podnositi = imperfective

For example:

• Ne mogu to podnijeti. = I can’t bear that.
• Teško podnosim stres. = I handle stress badly / I don’t tolerate stress well.

Because they both agree with naknadu, which is feminine singular and here appears in the accusative case.

The noun is:

• nominative: naknada = fee / charge
• accusative: naknadu

Since adjectives must match the noun in gender, number, and case, you get:

• visoka mjesečna naknada = a high monthly fee (nominative)
• visoku mjesečnu naknadu = a high monthly fee (accusative, as the direct object)

So:

• visoka → visoku
• mjesečna → mjesečnu
• naknada → naknadu

This is a standard feminine singular accusative pattern.

Because it is the direct object of podnijeti.

The verb podnijeti is acting on something: what can’t I bear?
Answer: visoku mjesečnu naknadu.

In Croatian, direct objects are often in the accusative.

Compare:

• Vidim kuću. = I see the house.
• Imam knjigu. = I have a book.
• Ne mogu podnijeti naknadu. = I can’t bear the fee.

So:

• nominative: naknada
• accusative: naknadu

The dictionary form is naknada.

That is the nominative singular form, which is the form you would usually look up in a dictionary.

Case forms here:

• naknada = nominative singular
• naknadu = accusative singular

The word naknada can mean:

• fee
• charge
• compensation
• allowance
• payment

The exact translation depends on context. In this sentence, fee or monthly charge is the most natural interpretation.

Because Croatian does not have articles like English the and a/an.

So visoku mjesečnu naknadu could mean:

• a high monthly fee
• the high monthly fee

Context tells you which one is meant.

This is normal in Croatian. For example:

• Imam knjigu. = I have a book / the book
• Kupio sam auto. = I bought a car / the car

If definiteness matters, Croatian usually shows it through context, word order, or additional wording rather than articles.

Yes, you can say Ja ne mogu podnijeti..., but it is usually unnecessary.

Croatian often drops subject pronouns because the verb form already shows who the subject is.

Here:

• mogu = I can

So ja is understood automatically.

That means:

• Ne mogu podnijeti visoku mjesečnu naknadu.
• Ja ne mogu podnijeti visoku mjesečnu naknadu.

Both are correct, but the version without ja is more neutral and natural in many situations.

You might include ja for emphasis, such as:

• Ja ne mogu podnijeti tu naknadu, ali on može. = I can’t bear that fee, but he can.

No, Croatian word order is fairly flexible, but the original order is very natural.

Standard neutral order:

• Ne mogu podnijeti visoku mjesečnu naknadu.

You may also hear variations, especially for emphasis:

• Visoku mjesečnu naknadu ne mogu podnijeti.
• Ne mogu visoku mjesečnu naknadu podnijeti.

These are grammatically possible, but they may sound more marked, literary, or emphatic depending on context.

For a learner, the original version is the safest and most natural.

Because visoku mjesečnu naknadu is the more natural adjective order.

In English we also tend to prefer a certain order of adjectives, and Croatian has similar tendencies. Here:

• mjesečnu describes the type/frequency of the fee: monthly
• visoku describes its quality or degree: high

In practice, visoka mjesečna naknada is the normal collocation.

You may occasionally see a different order for emphasis, but visoku mjesečnu naknadu is the neutral, idiomatic choice.

Not always. This is an important nuance.

podnijeti usually means to bear, to endure, to tolerate. It can work if you mean the fee is too burdensome, but if you specifically mean I don’t have enough money, Croatian often uses a different verb, such as:

• Ne mogu si priuštiti visoku mjesečnu naknadu. = I can’t afford the high monthly fee.

Or more directly:

• Ne mogu plaćati tako visoku mjesečnu naknadu. = I can’t pay such a high monthly fee.

So:

• Ne mogu podnijeti... = more like I can’t bear / handle it
• Ne mogu si priuštiti... = specifically I can’t afford it

If your intended meaning is financial inability, priuštiti si is often clearer.

They are an aspect pair:

• podnijeti = perfective
• podnositi = imperfective

Very roughly:

• podnijeti focuses on enduring something as a whole or reaching the limit of endurance
• podnositi focuses more on the ongoing process of tolerating something

Examples:

• Ne mogu to podnijeti. = I can’t bear that.
• Teško podnosim vrućinu. = I don’t tolerate heat well.

With mogu / ne mogu, perfective infinitives are common, so ne mogu podnijeti sounds completely natural.

The noun phrase in nominative would be:

• visoka mjesečna naknada

That is the form you would use if the phrase were the subject of a sentence.

For example:

• Visoka mjesečna naknada je problem. = A high monthly fee is a problem.

But in your original sentence, it is the object, so it changes to accusative:

• visoku mjesečnu naknadu

This contrast is useful to memorize:

• visoka mjesečna naknada → nominative
• visoku mjesečnu naknadu → accusative

They are related, but not the same.

• mjesečna naknada = monthly fee / monthly charge
• mjesečna rata = monthly installment / monthly payment

Use naknada when talking about a fee, service charge, membership fee, administrative fee, etc.

Use rata when talking about paying something in parts over time, such as a loan or purchase.

Examples:

• bankovna naknada = bank fee
• članarina je mjesečna naknada = membership is a monthly fee
• mjesečna rata kredita = monthly loan installment

So in your sentence, naknada suggests a recurring fee or charge, not necessarily an installment plan.

Usually the main stress in meaning would fall on the part that carries the new or important information.

For example:

• Ne mogu podnijeti visoku mjesečnu naknadu.

In context, a speaker might emphasize:

• ne mogu if the focus is inability
• podnijeti if the focus is tolerating/handling
• visoku if the focus is that the fee is too high
• mjesečnu naknadu if the focus is on the kind of expense

So spoken emphasis depends heavily on context. The sentence itself is neutral and natural as written.