Ona će prati odeću posle posla.

This is the future tense in Serbian.

It is built with:

• a short form of hteti = will
• plus the infinitive of the main verb

So here:

• ona = she
• će = will
• prati = to wash

So ona će prati literally means she will wash.

The short future forms are:

• ću = I will
• ćeš = you will
• će = he/she/it will
• ćemo = we will
• ćete = you all will
• će = they will

Because after će, Serbian normally uses the infinitive, not a present-tense form.

So:

• prati = to wash, the infinitive
• pere = washes / is washing, a present-tense form

That is why ona će prati is correct, not ona će pere.

Compare:

• Ona pere odeću. = She is washing / washes clothes.
• Ona će prati odeću. = She will wash clothes.

Because će is a clitic. In Serbian, clitics usually go in second position in the sentence or clause.

So the neutral order is:

• Ona će prati odeću posle posla.

Not normally:

• Će ona prati odeću...

This second-position rule is very common in Serbian and affects words like ću, će, sam, se, ga, je, and others.

Not always.

Serbian often drops subject pronouns because the verb form usually makes the subject clear from context.

So you can often say:

• Praće odeću posle posla.

or, in the separated form after another first element:

• Ona će prati odeću posle posla.

Including ona can:

• add emphasis
• make the subject clearer
• contrast her with someone else

So ona is grammatical and natural, but not always required.

Because it is in the accusative case, which is used here for the direct object of the verb prati.

The base form is:

• odeća = clothing / clothes

But as the object of wash, it becomes:

• odeću

So:

• Ona će prati odeću. = She will wash clothes.

This is a very common pattern for many feminine nouns ending in -a:

• nominative: žena
• accusative: ženu

Likewise:

• nominative: odeća
• accusative: odeću

Because odeća is a collective/uncountable noun in Serbian.

English uses clothes, which is grammatically plural, but Serbian usually uses odeća, which is grammatically singular feminine.

So even though the meaning is close to English clothes, the grammar works like a singular noun in Serbian.

For example:

• prljava odeća = dirty clothes
• čista odeća = clean clothes

Notice the adjective is also singular feminine:

• prljava
• čista

It literally means after work.

• posle = after
• posao = work / job

After the preposition posle, Serbian uses the genitive case.

So:

• nominative: posao
• genitive: posla

That is why you get:

• posle posla = after work

This is a very useful pattern:

• posle škole = after school
• posle ručka = after lunch
• posle sastanka = after the meeting

Yes, you could.

Serbian often has two ways to express this kind of future idea:

• će + infinitive → Ona će prati odeću
• će da + present tense → Ona će da pere odeću

Both are used in Serbian. The infinitive version is very standard and common. The da + present version is also very common, especially in everyday speech.

So these are both possible:

• Ona će prati odeću posle posla.
• Ona će da pere odeću posle posla.

The meaning is basically the same.

Often, yes.

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

• prati is imperfective
• oprati is perfective

Very roughly:

• prati focuses on the action as a process or general activity
• oprati focuses on completing the action

So:

• Ona će prati odeću can mean she will be washing clothes / she will wash clothes
• Ona će oprati odeću often sounds more like she will wash the clothes and get it done

If you are talking about one complete future action, many speakers would naturally say:

• Ona će oprati odeću posle posla.

But your original sentence is still grammatical and understandable.

Because Serbian can also use a contracted future form when the infinitive comes right before the future clitic.

For the verb prati, that gives:

• praće = she/he/it will wash

So instead of:

• Ona će prati odeću posle posla.

you might also see something like:

• Praće odeću posle posla.

This is especially useful because clitics usually do not stand at the very beginning by themselves. So Serbian often avoids starting a sentence with bare će.

In simple terms:

• after a subject or another first element: ona će prati
• when the verb starts the clause: often praće

The important sound here is ć, which is softer than č.

• će has a soft ć sound, something like a very soft tye
• odeću is pronounced roughly o-de-ću, again with that soft ć

A useful contrast:

• č is harder, more like English ch
• ć is softer and more palatal

Learners often need time to hear and produce the difference, so that is completely normal.