Το ανάπιασμα του προζυμιού αρχίζει τώρα.

The subject is Το ανάπιασμα του προζυμιού.

More specifically:

• Το ανάπιασμα = the main noun
• του προζυμιού = a genitive phrase that depends on that noun and tells you what the action concerns

So the verb αρχίζει is singular because the whole subject is singular: the feeding / refreshing of the starter.

Το is the neuter singular definite article: the.

It matches ανάπιασμα, which is a neuter singular noun.

So:

• το ανάπιασμα = the feeding / refreshing
• not just ανάπιασμα = feeding / refreshing in a more general or indefinite sense

Greek uses the definite article very regularly, often more often than English does.

Ανάπιασμα is a noun, not a verb.

It is a kind of action noun: a noun that names an action or process. In English, this often corresponds to forms like:

• feeding
• refreshing
• reviving
• working

So instead of saying something like We now begin to refresh the starter, Greek can package the action as a noun:

• Το ανάπιασμα του προζυμιού αρχίζει τώρα
  literally something like The refreshing of the starter begins now

This style is very natural in Greek.

Because after a noun like ανάπιασμα, Greek often uses the genitive to show what the action is connected with.

Here:

• το προζύμι = the starter / sourdough
• του προζυμιού = of the starter

So:

• το ανάπιασμα του προζυμιού = the feeding / refreshing of the starter

This is similar to English of the starter, even if English might sometimes prefer a different structure.

It is genitive singular.

The basic form is:

• το προζύμι = nominative / dictionary form

In this sentence it changes to:

• του προζυμιού = genitive singular

This is a very common pattern with neuter nouns in -ι.

Because many neuter nouns ending in -ι form the genitive singular in -ιού.

So the pattern is:

• το προζύμι
• του προζυμιού

You will see the same kind of change in other nouns too. The accent also shifts, so it is important to learn the whole form, not just the ending.

Because αρχίζει is third person singular present tense: it begins.

The subject is Το ανάπιασμα του προζυμιού, which is singular, so the verb must also be singular.

Compare:

• αρχίζω = I begin
• αρχίζεις = you begin
• αρχίζει = he/she/it begins

Here the subject is a thing/process, so English uses it begins, and Greek uses αρχίζει.

Because Greek, like English, often uses the present tense for something that is happening right now or is starting now.

So αρχίζει τώρα means:

• begins now
• is beginning now
• in context, even starts now

This is normal and natural. Greek does not need a separate progressive form like English is beginning.

Τώρα means now.

It tells you the time of the action:

• αρχίζει τώρα = begins now

It comes at the end here, which is very natural. Greek word order is flexible, so you might also see τώρα in other positions for emphasis, but this version is straightforward and neutral.

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

This sentence is in a neutral, natural order:

• Το ανάπιασμα του προζυμιού αρχίζει τώρα.

But Greek could move elements around for emphasis, for example:

• Τώρα αρχίζει το ανάπιασμα του προζυμιού.

That would put extra focus on now.

Even when the order changes, the endings and articles help show how the words fit together.

Not exactly simple possession, though it is related.

The genitive in Greek often covers meanings like:

• of
• belonging to
• related to
• concerning

Here του προζυμιού means something like of the starter or involving the starter.

So it is less about ownership and more about what the action is directed toward.

A very literal version would be:

• The feeding/refreshing of the starter begins now.

That helps show the Greek structure:

• Το ανάπιασμα = the feeding/refreshing
• του προζυμιού = of the starter
• αρχίζει = begins
• τώρα = now

Even if the natural English translation might be phrased differently, the Greek grammar is built this way.

A rough pronunciation guide is:

• Το = to
• ανάπιασμα = a-NA-pya-sma
• του = too
• προζυμιού = pro-zee-myoo
• αρχίζει = ar-KHEE-zee
• τώρα = TO-ra

A few notes:

• χ in αρχίζει is the Greek sound heard in German Bach or Scottish loch
• the stressed syllables are:
  • αναΠΙΑ? Wait, no — in ανάπιασμα, the stress is on νά: α-ΝΑ-πια-σμα
  • προζυμιΟΥ
  • αρχίΖΕΙ? No — the stress is on ζί: αρ-ΧΙ-ζει
  • ΤΩρα

So more carefully:

• α-ΝΑ-pya-sma
• pro-zee-myoo
• ar-KHEE-zee
• TO-ra

It sounds perfectly natural, especially in a cooking or baking context.

The structure with an action noun — το ανάπιασμα — is slightly more procedural or instruction-like than a simpler verbal sentence, but it is not unnatural.

It fits well in contexts like:

• recipe instructions
• baking guides
• demonstrations
• explanations of process

So it sounds like the speaker is describing a stage in the process: the starter refreshment begins now.