Learn Hardcore Croatian: U pravilu vikendom ne radimo, ali ovaj put imamo težak zadatak. - As a rule we do not work on weekends, but this time we have a difficult task.

U pravilu vikendom ne radimo
= As a rule, we don’t work on weekends (it’s our norm, our standard practice, but there can be exceptions).
Obično vikendom ne radimo
= We usually don’t work on weekends (statistically most weekends we don’t, but it sounds a bit more like “most of the time” than like a rule).

In many contexts you can swap them, but u pravilu sounds a bit more formal or “policy-like” than obično.

What is the grammar of u pravilu? What case is pravilu, and what is the base form?

The base form is pravilo (a neuter noun meaning “rule”).

In u pravilu:

u is a preposition that here takes the locative case (answering “in what?”).
pravilu is locative singular of pravilo.

So the pattern is:

Nominative: pravilo (a rule)
Locative: (u) pravilu (in the rule → “as a rule”)

The whole phrase has become a fixed expression meaning “as a rule / generally.”

Can I also say po pravilu instead of u pravilu? Are they different?

Both u pravilu and po pravilu exist and are understandable, but:

u pravilu = as a rule, generally speaking (very common set phrase).
po pravilu = according to the rule / according to the rules (slightly more literal “by the rulebook”).

In your sentence, U pravilu vikendom ne radimo sounds more natural. Po pravilu vikendom ne radimo is possible, but it subtly sounds more like you are referring to some established regulations.

What exactly is vikendom? Why is there no preposition like “u” or “za”?

Vikendom is a case form of vikend (“weekend”) used adverbially to mean “on weekends / at weekends.”

Base form: vikend (weekend)
Form in the sentence: vikendom → instrumental singular used in a time sense.

Croatian often uses the instrumental (without a preposition) to express “in/at/on [time period]” in a general, habitual sense:

danju – by day
noću – at night
zimi – in (the) winter
vikendom – on weekends

So Vikendom ne radimo = We don’t work on weekends.

Is there a difference between vikendom, vikendima, and za vikend?

Yes, there are small differences in nuance and usage:

vikendom – “on weekends” in general, as a habit.
- Vikendom ne radimo. – We don’t work on weekends.
vikendima – literally “on weekends” (instrumental plural); also used for repeated weekends, but somewhat less common in many dialects than vikendom for this meaning.
- Subotama i nedjeljama / vikendima radim od kuće.
za vikend – “for/during the weekend” (often referring to a particular upcoming or past weekend, not the general habit).
- Za vikend ne radimo. – We don’t work this weekend / on the weekend (often context decides whether it’s generic or specific).

In your sentence, vikendom clearly expresses a habitual, general statement.

Why is the verb radimo in the present tense? Doesn’t that mean “we are working” in English?

In Croatian, the present tense is used both for:

Current actions (like English “we are working now”):
- Sada radimo. – We are working now.
Habits and general truths (like English “we work / we don’t work”):
- Vikendom ne radimo. – We don’t work on weekends.

So ne radimo in this context is habitual present, equivalent to English simple present: “we don’t work.”

How does negation work in ne radimo? Where does ne go?

Ne is the basic negation particle and it comes directly in front of the verb in the present tense:

Radimo. – We work.
Ne radimo. – We don’t work.

Other examples:

Znam. → Ne znam. – I know. → I don’t know.
Razumijem. → Ne razumijem. – I understand. → I don’t understand.

Croatian often uses double negation with other negative words:

Ne radimo ništa. – We don’t do anything. (literally “We don’t work nothing.”)
Nikad ne radimo vikendom. – We never work on weekends.

So ne must be attached to the finite verb form.

What does ovaj put mean exactly? Is put here the word for “road” or something else?

Here put means “time, occasion”, not “road” (that would be put in a different sense, but the same word).

ovaj put = this time (on this occasion)

Grammar:

Base form (nominative): put (masculine noun)
In the sentence: ovaj put – ovaj is the masculine singular demonstrative (“this”), matching put in gender, number, and case (accusative = same form as nominative for inanimate masculine nouns).

So ali ovaj put imamo težak zadatak =
“but this time we have a difficult task.”

I’ve seen ovaj puta as well. Is there a difference between ovaj put and ovaj puta?

In modern standard Croatian, ovaj put is the neutral, preferred form for “this time.”

ovaj put – standard, neutral: this time

You may encounter ovaj puta in speech or some regional usage, but it’s generally considered colloquial or non-standard in contemporary Croatian.

For learning purposes, stick to ovaj put.

Why is it težak zadatak and not teška or teško zadatak?

Because the adjective must agree in gender, number, and case with the noun:

zadatak is masculine singular (nominative: zadatak, accusative: zadatak for inanimate nouns).
So the adjective must also be masculine singular, and here in the same case as the object:
- težak (masc. sing. nom./acc. for inanimate)

Comparisons:

težak zadatak – a difficult task (masculine)
teška knjiga – a difficult book (feminine)
teško pitanje – a difficult question (neuter)

Teško zadatak would be wrong, because teško is neuter and does not match the masculine noun zadatak.

Does težak here mean “heavy” or “difficult”? How do I know?

Težak can mean both:

heavy (physically):
- Težak kovčeg. – A heavy suitcase.
difficult, hard (mentally or emotionally):
- Težak zadatak. – A difficult task.
- Težak ispit. – A difficult exam.

Which meaning is intended depends on the noun and context.
With zadatak (task), the natural reading is “difficult”, not physically heavy.

What case is težak zadatak in here, and why?

In imamo težak zadatak:

imamo (we have) is a transitive verb and takes a direct object.
The direct object težak zadatak is in the accusative case (object case).

But for inanimate masculine nouns, the accusative singular = nominative singular:

Nominative: zadatak
Accusative: zadatak

The adjective težak also uses its masculine singular nominative/accusative (inanimate) form, which is the same shape: težak.

So the phrase looks like nominative, but functions grammatically as accusative (object of imamo).

Is the comma before ali required? How is punctuation with ali different from English “but”?

Yes, the comma before ali is standard and expected in this kind of sentence:

U pravilu vikendom ne radimo, ali ovaj put imamo težak zadatak.

This is very similar to English:

As a rule we don’t work on weekends, but this time we have a difficult task.

Like English but, Croatian ali normally connects two clauses, and you put a comma before it.
You don’t usually separate ali with commas on both sides in the middle of a clause (that would be unusual, just like in English with “but”).

Can I change the word order, for example Vikendom u pravilu ne radimo? Does it change the meaning?

Yes, you can change the word order, and Croatian allows quite a bit of flexibility. Some common variants:

U pravilu vikendom ne radimo, ali ovaj put imamo težak zadatak.
Vikendom u pravilu ne radimo, ali ovaj put imamo težak zadatak.
Vikendom, u pravilu, ne radimo, ali ovaj put imamo težak zadatak.

The basic meaning stays the same, but the emphasis shifts:

Starting with U pravilu stresses the idea of “as a rule / generally speaking.”
Starting with Vikendom stresses the time frame “at weekends” first.

All of these are grammatical; the version you have is a very natural choice.