Nastava počinje sutra.

Nastava is a feminine singular noun that usually refers to:

• teaching
• instruction
• classes in a general sense
• school lessons as a whole

So in this sentence, Nastava počinje sutra. most naturally means something like:

• Classes start tomorrow
• Instruction begins tomorrow
• School starts tomorrow (depending on context)

If you mean one single class period, Serbian often uses čas instead.

In Serbian, the present tense is often used for a planned or scheduled future event, especially when there is a time word like sutra (tomorrow).

So:

• Nastava počinje sutra. = Classes start tomorrow.

This works much like English sentences such as:

• The train leaves tomorrow.
• School starts next week.

So even though the verb looks present, the meaning is future because sutra makes the time clear.

The form počinje comes from the verb počinjati, which means to begin / to be beginning / to start.

Here:

• počinjem = I begin
• počinješ = you begin
• počinje = he/she/it begins

In this sentence, nastava is grammatically singular, so the verb is also singular: počinje.

Good question. These forms come from related verbs and express slightly different things.

• počinje = present of počinjati (imperfective)
• počne = present of početi (perfective)
• počeće = future form, roughly will begin

In everyday Serbian, počinje is very natural for schedules, timetables, and arranged future events:

• Nastava počinje sutra.

You can also say:

• Nastava će početi sutra.

That also means Classes will begin tomorrow, but it sounds a bit more explicitly future.

A simplified way to think about it:

• počinje = often used for scheduled future events
• će početi = standard future statement

Serbian does not have articles like a and the.

So nastava can mean:

• teaching
• the teaching
• classes
• the classes

The exact meaning depends on context.

That is why Nastava počinje sutra. does not need a separate word for the.

Because the subject is already stated: nastava.

The sentence structure is simply:

• Nastava = subject
• počinje = verb
• sutra = time expression

Serbian does not need an extra pronoun here.

In fact, adding one would usually sound unnecessary.

Sutra is an adverb of time, meaning tomorrow.

It tells you when the action happens.

So in the sentence:

• Nastava = subject
• počinje = verb
• sutra = time adverb

You can also move sutra around because Serbian word order is flexible:

• Nastava počinje sutra.
• Sutra nastava počinje.
• Nastava sutra počinje.

The first one is the most neutral and natural.

Grammatically, nastava is singular.

That is why the verb is also singular:

• nastava počinje = singular subject + singular verb

Even though English may translate it as classes, Serbian treats nastava as one general concept, not as a plural countable noun in this sentence.

That is very common with abstract or collective ideas.

A rough pronunciation guide:

• po = like po in pole, but shorter
• č = like ch in chocolate
• i
• nj = like ny in canyon
• e

So počinje sounds roughly like po-CHEE-nyeh.

Useful letter notes:

• č = ch
• nj = ny

And sutra is roughly SOO-tra.

Yes, in the right context it can.

Literally, nastava is more like classes / instruction / teaching, but in natural English people often translate it more freely as:

• School starts tomorrow.

That is especially common if you are talking about the beginning of the school term or the return to lessons.

So the most natural English translation depends on context, even if the Serbian wording stays the same.

Yes. Serbian word order is more flexible than English word order.

Possible versions include:

• Nastava počinje sutra.
• Sutra nastava počinje.
• Nastava sutra počinje.

These all mean basically the same thing, but the emphasis changes slightly.

• Nastava počinje sutra. = neutral
• Sutra nastava počinje. = stronger emphasis on tomorrow
• Nastava sutra počinje. = also possible, a bit more marked

For learners, the first version is the safest default.