Learn Hardcore Croatian: Za ručak pečem piletinu i dodajem malo ljutog umaka od rajčice. - For lunch I bake chicken and add a little spicy tomato sauce.

In Croatian, za + accusative often means “for” in the sense of purpose/time related to an activity or meal.
So za ručak literally = “for lunch”, i.e. as lunch / for the lunch meal.
Ručak is in the accusative singular (same form as nominative for this masculine inanimate noun).

What tense is pečem and why is it used if this could be a “future” idea in English?

Pečem is present tense (1st person singular) of peći (to roast/bake/grill depending on context).
Croatian often uses the present tense for:

what you’re doing right now, or
a planned/typical action in context (especially in conversation or recipes).

If you want an explicit future, you can use peći ću (I will roast/bake), but present is very natural here.

Is peći perfective or imperfective? How does aspect work in this sentence?

Peći is generally treated as imperfective (ongoing/process). It focuses on the activity of cooking/roasting.
A common perfective counterpart is ispeći (to roast/bake through; to finish baking).
So:

Pečem piletinu = “I’m roasting/baking chicken” (process)
Ispečem piletinu = “I roast/bake the chicken (to completion)” / “I’ll bake it (and finish)”

Both can appear with lunch context; it depends whether you emphasize the process or the completed result.

Why is it piletinu and not piletina?

Because piletinu is accusative singular, used for the direct object of the verb pečem (“I roast what?”).
Dictionary form piletina is nominative singular.
So:

Piletina je dobra. = “Chicken is good.” (subject → nominative)
Pečem piletinu. = “I’m roasting chicken.” (object → accusative)

Does piletina mean “chicken” as an animal or “chicken meat”?

Piletina usually means chicken meat (like “chicken” in English when talking about food).
The animal is pilet (chick) or kokoš (hen), pijetao (rooster), etc.
In cooking contexts, piletina/piletinu = chicken (meat).

Why is it dodajem (present tense) and not something like “I add” vs “I’m adding”?

Croatian present tense covers both “I add” and “I’m adding” depending on context.
Here it simply states another action you do while preparing lunch. If you want to stress “right now,” you can add sad(a) (now):
Sad dodajem malo... = “Now I’m adding a little...”

Why does malo cause ljutog umaka (genitive) instead of accusative?

Quantity expressions like malo (a little), puno (a lot), nekoliko (several) commonly take the genitive in Croatian.
So:

malo umaka = “a little (of) sauce” → genitive That’s why it’s ljutog umaka (genitive), not ljuti umak (nominative) or ljuti umak (accusative).

Why is the adjective ljutog and not ljuti?

Because adjectives agree with the noun in case, number, and gender.
Here the noun is umaka (genitive singular of umak, masculine), so the adjective must also be genitive masculine singular:

nominative: ljuti umak
genitive: ljutog umaka

What’s the difference between umak and sos?

Both can translate as “sauce,” but:

umak is very common in standard Croatian and cooking contexts.
sos is also used (and is widely understood), often sounding a bit more international/borrowed.

In many everyday situations, they’re interchangeable, but umak is a safe default in Croatian.

Why is it od rajčice (genitive) and not something like od rajčica or od rajčicu?

The preposition od (“of/from”) requires the genitive.
Rajčica (tomato) in genitive singular is rajčice.
So umak od rajčice = “tomato sauce” (literally “sauce of tomato”).

Genitive plural rajčica would mean “of tomatoes” (plural) and is possible if you mean multiple tomatoes as ingredients, but the common set phrase is od rajčice.

Could you also say rajčicni umak instead of umak od rajčice?

Yes, you can form an adjective to mean “tomato”:

rajčicin umak (more like “tomato’s sauce,” less common)
rajčični umak (adjectival “tomato sauce”)

However, umak od rajčice is extremely common and neutral, especially in everyday speech and recipes.

Is the word order fixed? Could I move Za ručak elsewhere?

Croatian word order is fairly flexible because cases mark roles. These are all natural with slightly different emphasis:

Za ručak pečem piletinu i dodajem... (sets the context first: “for lunch”)
Pečem piletinu za ručak i dodajem... (focus more on the action, then specify lunch)
Piletinu pečem za ručak... (emphasis on chicken)

Your original order is very natural and common.

How do I pronounce the tricky letters in this sentence: ručak, pečem, piletinu, ljutog, umaka, rajčice?

Key sounds:

č in ručak, pečem, rajčice ≈ “ch” in church
ć (not present here) is usually a softer “ch” than č (many learners initially pronounce them the same)
lj (not present here) is like the “lli” in million for many speakers
Stress is usually not written; just aim for clear vowels:
- ručak ≈ ROO-chak
- pečem ≈ PEH-chem
- rajčice ≈ RAI-chee-tseh (approx.)