Lakat joj je još malo natečen, pa stavlja hladnu mast prije spavanja.

Here joj is a dative pronoun, and Croatian often uses the dative to show possession, especially with body parts, clothes, and things closely connected to a person.

So:

• Lakat joj je natečen
  literally: The elbow to-her is swollen
• natural English: Her elbow is swollen

This is very common in Croatian. Instead of using a possessive adjective like njezin lakat, Croatian often prefers this dative structure in everyday speech.

Because joj and je are both clitics: short, unstressed words that follow special word-order rules.

In Croatian, clitics usually come right after the first stressed element in the sentence or clause, and they also have a fairly fixed internal order. In this sentence:

• Lakat = first stressed word
• then the clitic cluster comes: joj je

So Lakat joj je... is the natural order.

Lakat is in the nominative singular because it is the subject of the clause:

• Lakat joj je još malo natečen

The thing that is swollen is the elbow, so lakat stays in the subject form.

Also, lakat is a masculine noun.

Here natečen is a short-form adjective used predicatively, meaning it comes after je as part of is swollen.

So:

• lakat je natečen = the elbow is swollen

If you used natečeni, that would usually be the long form, more typical when the adjective stands before a noun:

• natečeni lakat = the swollen elbow

So the sentence uses the normal predicate pattern:

• X je natečen

Also, natečen is masculine singular, agreeing with lakat.

Here još malo means something like:

• still a little
• still slightly
• still somewhat

So još here means still, not more.

Examples:

• još je umorna = she is still tired
• još malo natečen = still a little swollen

The word malo softens the statement, making it sound less strong.

Pa is a very common connector in Croatian. In this sentence it means something like:

• so
• and so
• so then

It links the two ideas:

• her elbow is still a little swollen,
• so she applies cold ointment before bed.

It often sounds more conversational and natural than a heavier connector like zato.

Yes, stavlja literally means puts / is putting, but in Croatian it is also used naturally for applying something like cream or ointment.

So:

• stavlja mast = she applies ointment

The form stavlja is 3rd person singular present tense of the imperfective verb stavljati / stavljati? Actually the everyday pair is usually staviti (perfective) and stavljati (imperfective), but in many practical contexts learners first meet stavlja simply as the present-tense form meaning she puts/applies.

In this sentence it suggests a habitual or repeated action:

• she does this before sleeping

So English often translates it as:

• she applies
• she puts on

Croatian often drops subject pronouns when they are clear from the verb form or context.

Here stavlja already tells us the subject is he/she/it in the 3rd person singular. Because the meaning is already known from context, Croatian does not need to say ona.

So:

• stavlja = she is putting / she applies
• ona stavlja would only be used if you wanted extra emphasis or contrast

This is very normal in Croatian.

Because mast is the direct object of stavlja, so it goes into the accusative.

• nominative: hladna mast
• accusative: hladnu mast

The adjective changes clearly:

• hladna → hladnu

The noun mast itself does not visibly change here, because this type of feminine noun keeps the same form in nominative and accusative singular:

• mast = nominative singular
• mast = accusative singular

So the adjective shows the case most clearly.

It can suggest either, depending on context.

Most naturally here, a learner should understand it as:

• cool/cold ointment
• an ointment used to cool the swollen area

In real life, it could be:

• an ointment that feels cooling,
• or ointment kept cool before use.

So hladna keeps its basic meaning cold/cool, but in context the practical idea is something soothing for swelling.

Because after prije meaning before, Croatian normally uses a noun phrase in the genitive, not an infinitive.

Here spavanje is a verbal noun meaning sleeping, and after prije it becomes genitive:

• spavanje = sleeping
• prije spavanja = before sleeping

So literally:

• before sleeping

Very natural English translations are:

• before bed
• before going to sleep
• before sleeping

Yes, something like Lakat joj je još malo otekao or oteknut / natečen can be possible depending on style and nuance.

But natečen is a very common everyday adjective for swollen. It works well for body parts and sounds natural here.

So for a learner, the key point is:

• natečen = swollen
• it agrees with lakat in gender and number

The sentence as given is completely normal and idiomatic.