Learn Hardcore Croatian: Večeras ću prati rublje u perilici u kupaonici. - Tonight I will wash the laundry in the washing machine in the bathroom.

a present-tense form of htjeti (to want) used as an auxiliary: ću, ćeš, će, ćemo, ćete, će
- the infinitive of the main verb: prati (to wash)

So:

Večeras ću prati… = Večeras (this evening) + ću (I will) + prati (wash)

This is completely regular:

ću raditi – I will work
će učiti – he/she will study
ćemo gledati – we will watch

So instead of one fused future word, Croatian uses a helper word (ću) plus the infinitive.

Could we say veš instead of rublje? What’s the difference?

Yes, you will often hear:

Večeras ću prati veš u perilici u kupaonici.

rublje and veš both mean laundry / washing:

rublje – more neutral, a bit more standard
veš – very common in everyday speech, slightly more colloquial

Both are grammatically neuter, and in this sentence both are in the accusative singular (the object of prati).

What case are rublje, perilici, and kupaonici in, and why?

rublje – accusative singular (direct object of to wash)
- Što ću prati? – rublje (What will I wash? Laundry.)
perilici – locative singular feminine (location after u = in)
kupaonici – locative singular feminine (location after u = in)

With u meaning in (location, not movement), Croatian uses locative:

u perilici – in the washing machine
u kupaonici – in the bathroom

Why is it u perilici, not u perilica?

perilica is a feminine noun:

nominative singular: perilica (subject form)
locative singular: (u) perilici (in the washing machine)

After u with a static meaning (in), we use locative, so the ending changes:

Perilica je nova. – The washing machine is new. (nominative)
Rublje je u perilici. – The laundry is in the washing machine. (locative)

Why is it u kupaonici, not u kupaonicu?

Croatian distinguishes:

u + locative → in (location)
- u kupaonici – in the bathroom (where something is happening)
u + accusative → into (movement towards)
- u kupaonicu – into the bathroom (where you are going)

In the sentence, the action (washing) is already in the bathroom, not moving into it, so u kupaonici (locative) is correct.

Why is the word order Večeras ću prati rublje…? Can I move things around?

Croatian word order is quite flexible. All of these are grammatically possible, with slightly different emphasis:

Večeras ću prati rublje u perilici u kupaonici.
Rublje ću večeras prati u perilici u kupaonici. (emphasis on rublje)
U kupaonici ću večeras prati rublje u perilici. (emphasis on in the bathroom)

The chosen version is a neutral, natural-sounding order:

time: Večeras
auxiliary: ću
main verb: prati
object: rublje
location details: u perilici u kupaonici

Can I say Prat ću rublje večeras instead of Večeras ću prati rublje?

Yes, this is another standard future-tense pattern.

If the auxiliary ću/ćeš/… comes after the main verb, Croatian normally:

drops the final -i of the infinitive:
- prati ću → prat ću (standard)
- raditi ću → radit ću

So:

Večeras ću prati rublje.
Prat ću rublje večeras.

Both are correct. Many people in speech say prati ću, but in standard written Croatian prat ću is preferred.

What’s the difference between ću prati and ću oprati?

Both are grammatically correct but differ in aspect (how the action is viewed):

prati – imperfective: focuses on the process / activity
- Večeras ću prati rublje. → I will be doing laundry this evening. (activity)
oprati – perfective: focuses on completion / result
- Večeras ću oprati rublje. → I will (manage to) get the laundry washed this evening. (finished task)

Everyday meaning overlaps a lot, but:

use ću prati when you talk about the ongoing activity
use ću oprati if you want to stress that it will be finished

Why is večeras at the beginning? Could it go at the end?

Yes, večeras is flexible:

Večeras ću prati rublje… (very common)
Rublje ću prati u perilici u kupaonici večeras.
Prat ću rublje večeras u perilici u kupaonici.

Placing večeras at the beginning is a neutral, natural way to set the time frame first, like English Tonight I will…

Is rublje singular or plural? It looks like plural but doesn’t change.

rublje is:

neuter singular in form
a mass noun in meaning (like laundry or furniture)

So:

Rublje je prljavo. – The laundry is dirty. (singular verb je)
Rublje sam stavio u perilicu. – I put the laundry in the machine.

It doesn’t change for plural; you keep rublje and the verb stays singular.

Is kupaonica the only word for bathroom? I’ve seen kupaona as well.

Both exist:

kupaonica – more standard
kupaona – common in everyday speech, slightly shorter

So you might hear:

u kupaonici – in the bathroom
u kupaoni – in the bathroom (shorter form, same case)

In standard textbooks you’ll mostly see kupaonica / kupaonici.

How do you pronounce ću and why is there a special letter ć?

ću is pronounced approximately like “choo” in English chew, but shorter and sharper.
ć is a palatal t-sound, softer than č.

Roughly:

ć – soft: like the t in British when said quickly (a bit like ty)
č – hard: closer to ch in chocolate

So:

ću – [ću] – soft ć
ču – [ču] – hard č

In spelling, you must keep them apart; they can change meaning (e.g. ću – I will, ču doesn’t mean anything by itself here).

Could I leave out u kupaonici or u perilici? Is the sentence still correct?

Yes, these are optional details:

Večeras ću prati rublje. – I’ll wash the laundry this evening.
Večeras ću prati rublje u perilici. – I’ll wash the laundry in the washing machine.
Večeras ću prati rublje u kupaonici. – I’ll wash the laundry in the bathroom.

The original sentence just gives both locations:
what, where exactly (machine), and in which room. All versions are grammatically fine; you simply lose some detail when you omit phrases.