Lekar pregleda pacijenta.

Serbian normally does not use articles. So lekar can mean a doctor or the doctor, and pacijenta can mean a patient or the patient.

Context tells you which meaning is intended. That is very common in Serbian.

Because it is the direct object of the verb, so it is in the accusative case.

The basic form is pacijent.
In this sentence, the doctor examines the patient, so patient is the thing/person being examined. That makes it a direct object.

For many masculine animate nouns in Serbian, the accusative singular ends in -a:

• pacijent → pacijenta
• student → studenta
• lekar → lekara (if it were the object)

So the ending -a here does not mean the noun is feminine. It is just a case ending.

Because lekar is the subject of the sentence, and subjects normally appear in the nominative case.

Here:

• lekar = the one doing the action
• pacijenta = the one receiving the action

So lekar stays in its basic dictionary form.

Pregleda is the 3rd person singular verb form, matching lekar:

• ja pregledam = I examine
• ti pregledaš = you examine
• on/ona pregleda = he/she examines

So Lekar pregleda pacijenta literally has the structure:

• lekar = doctor
• pregleda = examines
• pacijenta = patient

Because Serbian usually does not need subject pronouns unless you want extra emphasis or contrast.

The verb ending already shows the person and number, and here the noun lekar is explicitly stated anyway. So adding on (he) would usually be unnecessary:

• Lekar pregleda pacijenta. = normal
• On pregleda pacijenta. = He examines the patient
• On, lekar, pregleda pacijenta. = possible, but marked/emphatic

This is about aspect, which is very important in Serbian.

• pregledati / pregleda is perfective
• pregledavati / pregledava is imperfective

Very roughly:

• pregleda focuses on a complete single examination
• pregledava focuses on an ongoing, repeated, or more general process

So learners often meet pregleda in simple model sentences, but in real-life context you may also hear:

• Lekar pregledava pacijenta. = The doctor is examining the patient.

This is a deeper topic, so if this distinction feels tricky, that is completely normal.

Yes. Serbian word order is fairly flexible because case endings show who is doing what.

The neutral, most basic order is:

• Lekar pregleda pacijenta.

But you can also say:

• Pacijenta pregleda lekar.
• Pregleda lekar pacijenta.

These alternatives are grammatical, but they change the focus or emphasis.

So for beginners, subject + verb + object is the safest default.

A rough pronunciation guide is:

• Lekar = LEH-kar
• pregleda = preh-GLEH-da
• pacijenta = pa-tsi-YEN-ta

A few useful notes:

• j is pronounced like English y in yes
• c is pronounced like ts
• every letter is usually pronounced clearly

So pacijenta sounds roughly like pa-tsi-yen-ta.

They are very close in meaning, and both can mean doctor.

• lekar is a standard Serbian word for a medical doctor
• doktor is also very common in everyday speech

In many situations, they can be used interchangeably. But doktor can also mean someone with a doctorate, depending on context.

In Serbian Cyrillic, it is:

Лекар прегледа пацијента.

Serbian officially uses both Latin and Cyrillic, and native speakers are expected to read both.