Learn Hardcore Croatian: Nakon večere perem posuđe, a ona čisti stol. - After dinner I wash the dishes, and she cleans the table.

Because nakon governs the genitive case. Večera (dinner) in the genitive singular is večere. Other examples: nakon ručka, nakon posla, nakon mene.

Why is there no ja before perem, but ona appears before čisti?

Croatian normally drops subject pronouns because person/number are clear from the verb ending (perem = I wash). Ona is included to mark a subject change and add contrast: I do one task, she does the other. Without it, … a čisti stol would be grammatical but can feel ambiguous or stylistically weak.

What does the conjunction a mean here, and how is it different from i?

a means “and/whereas”, often with a mild contrast or role-splitting: I do X, whereas she does Y.
i is a plain “and,” just adding another action. So perem posuđe, a ona čisti stol highlights the division of labor a bit more than perem posuđe i ona čisti stol.

Is the comma before a required? Should there be a comma after Nakon večere?

Yes, put a comma before a when it links two independent clauses: …, a ….
No comma is needed after a short initial time phrase like Nakon večere. The given punctuation is standard: Nakon večere perem posuđe, a ona čisti stol.

Why is it stol and not stola?

Stol is the direct object, so it’s in the accusative. For masculine inanimate nouns, the accusative equals the nominative: stol. Stola is genitive (e.g., bez stola, pokraj stola).

Can I say poslije večere instead of nakon večere? Any difference?

Yes. Poslije also takes the genitive (poslije večere). Style-wise, nakon can feel a bit more formal; poslije is very common in everyday speech. Avoid posle if you’re aiming for standard Croatian (that’s Serbian).

What’s the difference between perem and operem?

perem is imperfective (process/habit). It’s used for routines and ongoing actions: Nakon večere perem posuđe (I wash the dishes after dinner, habitually).
operem is perfective (single, completed event). The “present” of a perfective verb typically refers to the future: Operem posuđe pa idem spavati ≈ I’ll wash the dishes and then go to sleep. More commonly with future clitic: Oprat ću posuđe.

What about čisti vs očisti?

Same aspect contrast:

čisti (imperfective) = cleans/is cleaning (process or habit).
očisti (perfective) = will clean/clean up (one completed action). For a plan tonight: Ona će očistiti stol or Očistit će stol.

Could I use dok instead of a?

Yes. Dok means “while” and explicitly marks simultaneity:

Perem posuđe dok ona čisti stol (usually no comma when the dok-clause follows).
Dok ona čisti stol, perem posuđe (comma when the dok-clause comes first).
Compared to a, dok focuses more on the time overlap than on contrast.

Is posuđe countable? Why no plural?

Posuđe is a collective mass noun (neuter singular) meaning “dishes/kitchenware” as a set, so it stays singular: perem posuđe. If you want countable items, use specific nouns: tanjuri (plates), čaše (glasses), lonci (pots), etc.

Is suđe OK instead of posuđe?

In standard Croatian, posuđe is preferred; suđe is very common colloquially and widely understood. If you’re aiming for careful standard writing, stick to posuđe; in casual speech, suđe is fine.

Would briše stol or posprema stol be better than čisti stol?

čisti stol = cleans the table (generic cleaning).
briše stol / obriše stol = wipes the table (with a cloth).
posprema stol / pospremi stol = clears/tidies the table (removes dishes/items). Choose based on what “clean” means: wiping vs clearing vs general cleaning.

How do you conjugate prati and čistiti in the present?

prati (I wash): perem, pereš, pere, peremo, perete, peru.
čistiti (I clean): čistim, čistiš, čisti, čistimo, čistite, čiste.

Can I change the word order, e.g., Perem posuđe nakon večere, a ona čisti stol?

Yes. Fronting Nakon večere gives time emphasis; placing it later is equally correct: Perem posuđe nakon večere, a ona čisti stol. The core meaning stays the same.

How would I say this about tonight (a one-off plan) rather than a routine?

Use future and perfective for a single completed action:

Nakon večere ću oprati posuđe, a ona će očistiti stol. Note the clitic ću comes after the first stressed element of the clause.

Any spelling/diacritic gotchas?

Yes: use č in večera and čisti. Writing vecera/cisti is considered incorrect in standard Croatian. Also, in Croatian, stol = table; sto usually means “one hundred,” so stick with stol to avoid confusion.