Tura zaczyna się teraz.

In this sentence, tura most naturally means round, turn, or phase, depending on context.

For example:

• in a game: round
• in a conversation or activity where people take turns: turn
• in a process or competition: stage/round

So tura zaczyna się teraz is something like The round starts now or Your turn starts now, depending on the situation.

Zaczyna is the 3rd person singular present tense of zaczynać (to begin / to start).

The subject is tura, which is:

• singular
• feminine

In the present tense, Polish verbs agree mainly with person and number, not with gender, so for it starts, you use zaczyna.

Compare:

• tura zaczyna się = the round starts
• tury zaczynają się = the rounds start

In this sentence, się is part of the verb expression zaczynać się, which means to begin or to start.

This is very common in Polish:

• Film zaczyna się o ósmej. = The film starts at eight.
• Spotkanie zaczyna się jutro. = The meeting starts tomorrow.

Without się, zaczynać is often used more transitively, meaning to start something or to begin something:

• Zaczynam lekcję. = I am starting the lesson.

So:

• zaczynać się = to begin / to start (something begins)
• zaczynać = to start / begin (someone starts something)

Normally, no, not in this meaning.

Tura zaczyna się teraz is the natural way to say that the round itself is beginning now.

If you remove się, the sentence sounds incomplete or unnatural because zaczynać without się usually expects an object:

• Zaczynam pracę teraz. = I’m starting work now.

So for events, meetings, films, rounds, etc., Polish usually prefers zaczyna się.

Tura is in the nominative case because it is the subject of the sentence.

It is the thing that is beginning:

• Tura = subject
• zaczyna się = verb
• teraz = adverb

You can think of the structure as:

• [The round] [starts] [now].

Yes, teraz can move around because Polish word order is fairly flexible.

All of these are possible:

• Tura zaczyna się teraz.
• Teraz tura zaczyna się.
• Teraz zaczyna się tura.
• Tura teraz zaczyna się.

But they do not all sound equally natural in every context.

Tura zaczyna się teraz is a very normal neutral sentence. Putting teraz at the end often gives a natural now-focus, similar to English The round starts now.

A very common alternative is:

• Teraz zaczyna się tura.

That can feel slightly more like Now the round is starting.

Grammatically, zaczyna się is present tense.

However, in Polish, present tense can sometimes refer to something happening right now or something about to happen now, especially with time words like teraz.

So in this sentence it means:

• is starting now or
• starts now

If you want a clearly future perfective form, you could use:

• Tura zacznie się teraz.

But with teraz, zaczyna się is very natural.

This is a question of aspect.

• zaczyna się comes from zaczynać się — imperfective
• zacznie się comes from zacząć się — perfective

Very roughly:

• zaczyna się focuses on the beginning as a process or present event
• zacznie się points to a single completed starting point in the future

Examples:

• Film zaczyna się teraz. = The film is starting now / starts now.
• Film zacznie się za godzinę. = The film will start in an hour.

In your sentence, zaczyna się teraz sounds very natural because the start is happening at this moment.

Because Polish does not use articles like a, an, or the.

So tura can mean:

• a round
• the round

The context tells you which one is meant.

That is very normal in Polish:

• Film jest dobry. = The film is good or A film is good, depending on context
• Tura zaczyna się teraz. = The round starts now

No. Polish usually does not need an explicit subject pronoun if the subject is already stated or understood.

Here, tura is the subject, so there is no need for anything like English it.

Polish often avoids extra pronouns unless they are needed for contrast or emphasis.

Się is usually pronounced approximately like shenh or sheh with a nasal vowel at the end, though in everyday speech the nasal quality is often weaker than learners expect.

A rough pronunciation of the whole sentence is:

TOO-ra za-CHY-na shyeh TE-ras

A few useful points:

• cz in zaczyna sounds like English ch in chop
• rz in teraz here sounds like zh (like the s in measure)
• Polish stress is usually on the second-to-last syllable:
  • TU-ra
  • za-CZY-na
  • TE-raz

Yes, absolutely, if the context is a round in a game, contest, or match.

• tura often means turn, round, shift, or stage
• runda more specifically means round, especially in games, sports, competitions, boxing, etc.

So in some contexts:

• Runda zaczyna się teraz may sound more natural than Tura zaczyna się teraz

But if the intended meaning is more like turn or phase, then tura is the better word.