Learn Hardcore Croatian: Vikendom ponekad imamo dodatni trening u dvorani. - On weekends we sometimes have an extra training session in the hall.

Za vikend ponekad imamo dodatni trening. – “On the weekend we sometimes have extra practice.”
(This sounds a bit more like this coming / that weekend, not a general habit.)

In the original sentence, vikendom expresses a habitual action: something that regularly happens on weekends in general.

Could you explain the word ponekad? How often is that, and are there similar words?

Ponekad means “sometimes / occasionally” – not very often, but not rare either.

Similar words and nuances:

povremeno – occasionally, from time to time (a bit more formal)
katkad – also “sometimes” (slightly literary/old-fashioned in some regions, but still used)
nekad / nekada – can mean “once / once upon a time / some time ago”; in some dialects it can also mean “sometimes”, which can be confusing, so learners usually avoid using it that way.

In the sentence:

Vikendom ponekad imamo dodatni trening u dvorani.
→ “On weekends we sometimes have extra training in the gym.”

So the training does not happen every weekend, just on some weekends.

Why is the word order “Vikendom ponekad imamo …”? Could it also be “Ponekad vikendom imamo …”?

Yes, you can change the order:

Vikendom ponekad imamo dodatni trening u dvorani.
Ponekad vikendom imamo dodatni trening u dvorani.

Both are correct and natural.

Croatian word order is relatively flexible. Both vikendom (time expression) and ponekad (frequency adverb) like to appear near the beginning of the sentence.

Subtle feel:

Vikendom ponekad… – slightly more focus on “as for weekends (as opposed to weekdays), sometimes we have…”
Ponekad vikendom… – slightly more neutral “sometimes, on weekends we have…”

In normal conversation, speakers freely alternate; there is no strong rule here.

Why is there no explicit word for “we” in the Croatian sentence?

In Croatian, subject pronouns (ja, ti, on, mi, vi, oni) are usually dropped because the verb ending already shows the person and number.

imamo = “we have” (1st person plural present)

So:

(Mi) ponekad imamo dodatni trening.
- The mi (“we”) is optional.
- Native speakers generally say just Imamo… unless they want to emphasize it.

You would include mi for contrast or emphasis:

Mi ponekad imamo dodatni trening, ali oni nemaju.
“We sometimes have extra training, but they don’t.”

Why is it imamo and not something like a future form if this is a routine? Does Croatian use present tense for habits?

Yes. Croatian, like English, uses the present tense for habits / regular activities:

Vikendom ponekad imamo dodatni trening.
“On weekends we sometimes have extra training.” (habitual present)

If you wanted to talk about future weekends in general, you could use the future:

Vikendom ćemo ponekad imati dodatni trening.
“On weekends we will sometimes have extra training.”

But for a general statement about what typically happens, present tense (imamo) is the normal choice.

What form is dodatni, and why does it end in -i and not -a or -o?

Dodatni is an adjective meaning “additional / extra”.

Adjectives in Croatian must agree with the noun in:

gender (masculine / feminine / neuter)
number (singular / plural)
case

The noun trening is:

masculine
singular
accusative (because it is the direct object of imamo)

Masculine singular accusative of an animate noun looks like the genitive (ending in -a), but trening here is inanimate, so the form is the same as nominative: trening. The adjective before it uses the masculine singular accusative form dodatni:

(mi) imamo što? – dodatni trening
“we have what? – extra training”

Compare:

dodatni trening – extra training (masc. sg.)
dodatna vježba – extra exercise (fem. sg.)
dodatno pitanje – additional question (neut. sg.)
dodatni treninzi – extra trainings/sessions (masc. pl.)

So -i here is just the regular masculine singular ending for this case pattern.

What is the difference between dodatni and dodatno?

Both come from the same root, but:

dodatni is an adjective: “additional / extra” (agrees with a noun)
- dodatni trening – extra training
- dodatna knjiga – an additional book
dodatno is usually:
- an adverb: “additionally, extra, in addition”
  - Morat ćemo dodatno trenirati. – “We’ll have to train additionally / train more.”
- or neuter singular adjective form when it directly modifies a neuter noun:
  - dodatno pitanje – an additional question

In your sentence, you must use dodatni because it directly describes the noun trening.

What exactly does trening mean in Croatian? Is it like “training” in English, or more like “practice”?

Trening in Croatian is usually:

a training session / practice session, often in sports or fitness,
the activity where a team or person practices.

So dodatni trening here is most naturally:

“extra practice” (e.g. football, basketball training)
or “an additional training session”

Compare:

Imamo trening svaki dan. – “We have practice every day.”
Teretana – gym (the place)
vježba – exercise, drill, practice (more general; can be school, music, etc.)

In many contexts trening ≈ sports practice in English.

What form is dvorani, and what is the basic (dictionary) form of that word?

The basic (dictionary) form is:

dvorana – “hall”, “sports hall”, “gym” (in the sense of a sports hall)

Dvorani here is the locative singular form of dvorana.

Feminine noun dvorana declines like this (singular):

Nominative: dvorana – the hall (subject)
Genitive: dvorane – of the hall
Dative: dvorani – to the hall
Accusative: dvoranu – (into) the hall
Locative: dvorani – in the hall
Instrumental: dvoranom – with/by the hall

After the preposition u, locative is used for location:

u dvorani – in the hall / in the gym (where?)
Accusative would be u dvoranu – into the hall (movement, where to?).

So the sentence literally means:

“We sometimes have extra training in the hall/gym.”

Why is it u dvorani and not u dvoranu? What is the difference between those two?

The preposition u can take either:

locative – for location (where something is)
accusative – for movement into (where something is going)

So:

u dvorani (locative) – in the hall / in the gym (static location)
u dvoranu (accusative) – into the hall / into the gym (movement into)

Your sentence describes where the training takes place, not movement:

…imamo dodatni trening u dvorani.
= We have (hold) the extra training in the gym.

Examples:

Ulazimo u dvoranu. – We’re going into the hall. (movement → accusative)
Čekamo u dvorani. – We’re waiting in the hall. (location → locative)

Could dvorana mean a typical school gym, or is it more like a theater hall?

Dvorana is a general word for a large enclosed hall, and context decides the type:

sportska dvorana – sports hall, school gym
koncertna dvorana – concert hall
plesna dvorana – dance hall

In everyday speech, when people involved in sports say just dvorana, they almost always mean the sports hall / gym. So in your sentence it is very natural to translate u dvorani as “in the gym”.

Is vikendom grammatically singular or plural? It sounds like “weekends”.

Grammatically, vikendom is:

instrumental singular of vikend.

Semantically, when used in this adverbial way, it covers the idea of “on weekends (in general)” – so it behaves like a generic time expression, not specifically “one weekend”.

You can also say:

vikendima – instrumental plural, also meaning “on weekends”

But vikendom (singular instrumental used adverbially) is more common and feels more idiomatic.

So:

vikendom – standard, very common
vikendima – also possible, a bit more explicit about “many weekends”

Where can ponekad go in the sentence? Is the position fixed?

The position of ponekad is not fixed. Common options are:

Vikendom ponekad imamo dodatni trening u dvorani.
Ponekad vikendom imamo dodatni trening u dvorani.
Vikendom imamo ponekad dodatni trening u dvorani.
Ponekad imamo dodatni trening u dvorani vikendom. (less usual, but possible)

Typical and most natural are the first two, where ponekad appears near the beginning.

General rule: adverbs of frequency (često, rijetko, ponekad) usually go:

near the verb, or
near the beginning of the sentence.

Changing the position can shift emphasis slightly, but the basic meaning stays the same.

How would you pronounce Vikendom ponekad imamo dodatni trening u dvorani? Any tricky sounds for English speakers?

A rough phonetic guide (stressed syllables in CAPS):

VIK-en-dom PO-ne-kad I-ma-mo DO-dat-ni TRE-ninG u dvo-RA-ni

Notes for English speakers:

r is tapped/flapped (like the Spanish r, or the American quick t in “water”).
dvor- starts with a consonant cluster dv, both consonants are pronounced: dvo-RA-ni.
Vowels are short and clear; each written vowel corresponds to one sound.
Final g in trening is a hard g (as in “go”), not “j”.

All words are pronounced very close to how they are spelled.