Odgovoran poslodavac daje obuku kandidatu.

Here is the basic breakdown:

• Odgovoran = responsible
  
  • an adjective
  • it describes poslodavac
• poslodavac = employer
  
  • the subject of the sentence
  • nominative singular
• daje = gives / is giving / provides
  
  • the verb
  • 3rd person singular present
• obuku = training
  
  • the direct object
  • accusative singular of obuka
• kandidatu = to the candidate
  
  • the indirect object / recipient
  • dative singular of kandidat

So the structure is basically:

[adjective + subject] + verb + direct object + indirect object

Because kandidatu is in the dative singular.

In Serbian, the dative often marks the recipient of something, where English would usually use to:

• daje kandidatu = gives to the candidate

The dictionary form is kandidat.
When it becomes dative singular, it changes to kandidatu.

So:

• kandidat = candidate
• kandidatu = to the candidate

Because Serbian often expresses that meaning through case endings instead of a preposition.

English says:

• gives training to the candidate

Serbian says:

• daje obuku kandidatu

The idea of to the candidate is already built into the dative ending -u in kandidatu.

This is very common in Serbian with verbs like:

• dati nekome nešto = give someone something
• reći nekome = say to someone
• pomoći nekome = help someone

So the case ending does the work that to does in English.

Because obuku is the accusative singular form of obuka.

• obuka = nominative singular, the dictionary form
• obuku = accusative singular

In this sentence, obuku is the direct object of daje, so it needs the accusative.

Compare:

• Obuka je važna. = Training is important.
  
  • obuka is the subject, so nominative
• Poslodavac daje obuku. = The employer gives training.
  
  • obuku is the object, so accusative

Since obuka is a feminine noun ending in -a, its accusative singular usually changes to -u.

Because adjectives in Serbian must agree with the noun they describe.

Here, odgovoran describes poslodavac, which is:

• masculine
• singular
• nominative

So the adjective must also be:

• masculine
• singular
• nominative

That gives:

• odgovoran poslodavac = a responsible employer

If the noun changed, the adjective would change too. For example:

• odgovorna firma = a responsible company
• odgovorni poslodavci = responsible employers

This agreement is a major feature of Serbian grammar.

Daje is the 3rd person singular present tense form of the verb.

It means:

• gives
• is giving
• provides

depending on context.

The subject is poslodavac, which is he/she/it grammatically, so the verb is in 3rd person singular:

• ja dajem = I give
• ti daješ = you give
• on/ona/ono daje = he/she/it gives

Here:

• poslodavac daje = the employer gives

Because the sentence needs a finite verb, not the dictionary form.

• dati is an infinitive: to give
• daje is a conjugated form: gives / is giving

A full Serbian sentence normally needs a conjugated verb:

• Poslodavac daje obuku kandidatu. = correct
• Poslodavac dati obuku kandidatu. = not correct

Also, daje is an imperfective form, which often suggests a general, repeated, or ongoing action. So this sentence sounds like a general statement such as:

• A responsible employer provides training to the candidate

Usually it sounds like a general statement or a habitual action, because daje is present tense and commonly used with an imperfective meaning.

So it can suggest something like:

• A responsible employer provides training to a candidate
• A responsible employer gives training to the candidate

If you wanted to emphasize one completed act, Serbian would often use a different form or a clearer context, for example in the past:

• Poslodavac je dao obuku kandidatu. = The employer gave training to the candidate.

So in your sentence, the feeling is more general than one-time completed event.

No, Serbian word order is fairly flexible because cases show the grammatical roles.

The sentence you have is a very natural neutral order:

• Odgovoran poslodavac daje obuku kandidatu.

But other orders are also possible, depending on emphasis:

• Poslodavac daje obuku kandidatu.
• Kandidatu odgovoran poslodavac daje obuku.
• Obuku kandidatu daje odgovoran poslodavac.

These all keep roughly the same core meaning because:

• poslodavac is still nominative
• obuku is still accusative
• kandidatu is still dative

So the endings tell you who is doing what to whom.

Because Serbian does not have articles like English.

So:

• poslodavac can mean an employer, the employer, or just employer in a general sense
• kandidatu can mean to a candidate or to the candidate
• obuku can mean training or the training, depending on context

English must choose between a/an and the, but Serbian usually leaves that to context.

That is why one Serbian sentence can correspond to several natural English translations.

The dictionary forms are:

• odgovoran = responsible
• poslodavac = employer
• davati / dati = to give
  
  • depending on whether you are looking at the imperfective/perfective pair
• obuka = training
• kandidat = candidate

The forms in the sentence are:

• odgovoran → same as dictionary form here
• poslodavac → same as dictionary form here
• daje → conjugated verb form
• obuku → from obuka
• kandidatu → from kandidat

Learning to move between the dictionary form and the sentence form is a key skill in Serbian.