Ne mogu ni spavati zbog stresa.

Here ni means even in a negative sentence, so Ne mogu ni spavati is I can’t even sleep.

In Croatian, ni often appears with negation:

• Ne vidim ga. = I don’t see him.
• Ne vidim ga ni danas. = I don’t even see him today.

So without ni, Ne mogu spavati just means I can’t sleep.
With ni, it becomes stronger: I can’t even sleep.

Because in Croatian, the negative particle ne is usually written separately from the verb:

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

This is normal for most verbs. English speakers sometimes expect a single word, but Croatian usually keeps them separate.

A few very common forms are exceptions and are written together, such as:

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

But ne mogu stays as two words.

Because after the modal verb moći (can / to be able to), Croatian uses the infinitive.

So:

• mogu spavati = I can sleep
• ne mogu spavati = I can’t sleep

This works much like English:

• I can sleep
• I can’t sleep

Here:

• mogu = I can
• spavati = to sleep

Because Croatian often leaves out subject pronouns when they are already clear from the verb form.

Mogu already tells us the subject is I:

• mogu = I can
• možeš = you can
• može = he/she/it can

So Ne mogu ni spavati zbog stresa naturally means I can’t even sleep because of stress without needing ja.

You could say Ja ne mogu ni spavati zbog stresa, but that adds emphasis, like: I can’t even sleep because of stress.

Because the preposition zbog requires the genitive case.

The noun is:

• stres = stress

After zbog, it changes to:

• stresa

So:

• zbog stresa = because of stress

This is a very important pattern to remember:

• zbog kiše = because of the rain
• zbog posla = because of work
• zbog stresa = because of stress

Zbog means because of, due to, or on account of.

In this sentence:

• zbog stresa = because of stress

It introduces the cause or reason for the problem.

So the structure is:

• Ne mogu ni spavati = I can’t even sleep
• zbog stresa = because of stress

Yes. That is completely correct.

The difference is:

• Ne mogu spavati zbog stresa. = I can’t sleep because of stress.
• Ne mogu ni spavati zbog stresa. = I can’t even sleep because of stress.

So ni adds emphasis. It suggests that the stress is so bad that even sleep is difficult.

Not completely. Croatian word order is fairly flexible, but different orders change the emphasis.

The original:

• Ne mogu ni spavati zbog stresa.

This is natural and emphasizes ni spavati = even sleep.

You could also say:

• Zbog stresa ne mogu ni spavati.

This puts more focus on the cause: because of stress.

Both are natural. Croatian often moves parts of the sentence around for emphasis, but the original version is very standard.

Yes, in other contexts ni can mean nor or neither, but in this sentence it works more like even in a negative sentence.

For example:

• Ni Ana ni Marko nisu došli. = Neither Ana nor Marko came.

But here:

• Ne mogu ni spavati. = I can’t even sleep.

So the meaning of ni depends on the structure around it.

Good question. These verbs are related but not the same:

• spavati = to sleep
• zaspati = to fall asleep

So:

• Ne mogu spavati. = I can’t sleep.
• Ne mogu zaspati. = I can’t fall asleep.

In everyday speech, people sometimes use ne mogu spavati even when they really mean they are unable to fall asleep, but strictly speaking, zaspati is more precise for fall asleep.

It breaks down like this:

• Ne = not
• mogu = I can
• ni = even
• spavati = sleep / to sleep
• zbog stresa = because of stress

So the sentence structure is basically:

not + can + even + sleep + because of stress

A natural English rendering is: I can’t even sleep because of stress.

Yes, you may also hear od stresa, and it can sound natural in everyday speech.

Very roughly:

• zbog stresa = because of stress
• od stresa = from stress / due to stress

In many contexts they are close in meaning.
However, zbog stresa is a very clear and standard way to express cause, and it is an excellent choice for learners.

So:

• Ne mogu ni spavati zbog stresa. = very standard
• Ne mogu ni spavati od stresa. = also natural in many situations