Ovo je radijski prijemnik.

This is a very common question.

In Ovo je radijski prijemnik, ovo means this in the sense of this thing here. It is very often used when you are identifying something:

• Ovo je knjiga. = This is a book.
• Ovo je moj brat. = This is my brother.
• Ovo je radijski prijemnik. = This is a radio receiver.

So even though prijemnik is masculine, Croatian often uses ovo in this type of sentence because you are first pointing to or presenting something, and then saying what it is.

By contrast, ovaj prijemnik means this receiver, where ovaj directly modifies the masculine noun prijemnik.

So:

• Ovo je radijski prijemnik. = This is a radio receiver.
• Ovaj prijemnik je radijski. = This receiver is radio-related / is a radio receiver type.

Je is the 3rd person singular present tense of the verb biti, which means to be.

So:

• ja sam = I am
• ti si = you are
• on / ona / ono je = he / she / it is

In this sentence:

• Ovo je radijski prijemnik.
• literally: This is a radio receiver.

Croatian normally includes je here. You cannot leave it out in standard Croatian.

Radijski is an adjective meaning radio, radio-related, or pertaining to radio.

It comes from radio and is turned into an adjective with the ending -ski.

So:

• radio = radio
• radijski = radio-, radio-related

Examples:

• radijska postaja = radio station
• radijski program = radio program
• radijski prijemnik = radio receiver

In English, we often use a noun directly before another noun, as in radio receiver. Croatian usually prefers an adjective here: radijski prijemnik.

Prijemnik means receiver.

It is related to the verb primiti = to receive, and the noun prijem = reception / receiving.

The ending -nik is often used to form nouns for things or people associated with an action or function.

So prijemnik is basically something that receives.

You do not need to analyze it every time, but noticing these word-building patterns can really help with vocabulary.

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

So:

• prijemnik can mean a receiver, the receiver, or just receiver
• the exact meaning depends on context

In Ovo je radijski prijemnik, English naturally says This is a radio receiver, but Croatian simply says Ovo je radijski prijemnik with no article.

It is in the nominative case.

That is because in a sentence like This is X, the thing being identified is normally in the nominative in Croatian.

So:

• Ovo je radijski prijemnik.
• radijski prijemnik = nominative singular

Also, radijski agrees with prijemnik:

• masculine
• singular
• nominative

That is why it is radijski prijemnik, not some other form.

A good clue is the ending.

Many Croatian masculine nouns in the nominative singular end in a consonant, and prijemnik ends in -k, so it is masculine.

That is why the adjective is also in the masculine singular nominative form:

• radijski prijemnik

If the noun were feminine or neuter, the adjective would change:

• masculine: radijski
• feminine: radijska
• neuter: radijsko

A rough pronunciation guide:

• ovo ≈ OH-voh
• je ≈ yeh
• radijski ≈ rah-DEE-yee-skee
• prijemnik ≈ pree-YEM-neek

A few useful pronunciation notes:

• j is pronounced like English y
• je sounds like ye
• ij is usually pronounced as two vowels with a y-like glide between them
• stress can vary by dialect, but the above approximation is good enough for a learner

So the whole sentence sounds roughly like:

OH-voh yeh rah-DEE-yee-skee pree-YEM-neek

Yes, Croatian word order is more flexible than English, but the neutral, standard order here is:

• Ovo je radijski prijemnik.

You may also hear:

• Radijski prijemnik je ovo.

But that sounds marked or emphatic, as if you are specially emphasizing radio receiver or contrasting it with something else.

For ordinary identification, stick with:

• Ovo je radijski prijemnik.

Yes, in many situations you could.

Both ovo and to can appear in identification sentences:

• Ovo je radijski prijemnik.
• To je radijski prijemnik.

Very roughly:

• ovo often feels like this here
• to often feels like that / that thing / it

But in real usage, to je is extremely common and often translates naturally as this is or that is, depending on context.

If you are physically presenting something near you, ovo is a very natural choice.

Because in Croatian, adjectives normally come before the nouns they describe.

So:

• radijski prijemnik = radio receiver
• velika kuća = big house
• novi auto = new car

This is similar to English word order, but the difference is that Croatian often uses an adjective where English might use a noun modifier.

English:

• radio receiver

Croatian:

• radijski prijemnik

Not usually in casual everyday speech.

If you mean the ordinary device people listen to, Croatian speakers will often simply say:

• radio

For example:

• Ovo je radio. = This is a radio.

Radijski prijemnik is more formal, technical, or precise. It is a correct expression, but it sounds more like radio receiver than the everyday English word radio.

So the sentence is grammatically fine, but the style is a bit more technical.