Η μαζική ωρίμανση αρχίζει μετά την αυτόλυση.

Η is the feminine singular definite article, meaning the.

It is used here because ωρίμανση is a feminine singular noun, so the article has to match it in gender, number, and case.

• η = the for feminine singular in the nominative case
• ωρίμανση = a feminine singular noun

So Η μαζική ωρίμανση means the mass maturation / the massive ripening, depending on context.

Because the adjective has to agree with the noun it describes.

Here:

• ωρίμανση is feminine
• singular
• nominative

So the adjective μαζικός changes to the matching form μαζική.

This is a very common Greek pattern:

• masculine: μαζικός
• feminine: μαζική
• neuter: μαζικό

So μαζική ωρίμανση is correct because both words are feminine singular nominative.

ωρίμανση is a noun meaning maturation, ripening, or aging, depending on context.

Grammatically, in this sentence it is:

• feminine
• singular
• nominative

It is the subject of the verb αρχίζει.

So the structure is basically:

• Η μαζική ωρίμανση = the subject
• αρχίζει = begins
• μετά την αυτόλυση = after the autolysis

Αρχίζει is the 3rd person singular present tense of αρχίζω, meaning to begin or to start.

It is in the 3rd person singular because the subject, Η μαζική ωρίμανση, is singular.

So:

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

Since ωρίμανση is a thing, English translates it as it begins, but Greek does not need a separate word for it here.

Greek usually does not use an explicit subject pronoun when the verb ending already shows the person and number.

In English, you must say:

• it begins

In Greek, the verb ending already tells you it is 3rd person singular, so it is normally omitted.

That is why Greek says simply:

• αρχίζει = begins / it begins

The actual subject is already stated as Η μαζική ωρίμανση.

Because μετά is a preposition, and in Modern Greek it normally takes the accusative case when it means after.

So:

• η αυτόλυση = the autolysis, nominative
• την αυτόλυση = the autolysis, accusative

That is why the sentence says:

• μετά την αυτόλυση = after the autolysis

The article changes from η to την because of the case required by μετά.

Yes. Αυτόλυση is feminine.

Its basic form is:

• η αυτόλυση = the autolysis

In this sentence it appears as:

• την αυτόλυση

That is the accusative singular form, used after μετά.

Many Greek nouns ending in -ση are feminine, so this is a useful pattern to recognize.

Yes, Greek word order is more flexible than English word order because case endings and verb forms carry a lot of grammatical information.

The neutral, straightforward order here is:

• Η μαζική ωρίμανση αρχίζει μετά την αυτόλυση.

But Greek could also move things around for emphasis, for example:

• Μετά την αυτόλυση αρχίζει η μαζική ωρίμανση.

This still means the same thing: Mass maturation begins after autolysis.

The second version emphasizes the time relationship a bit more.

The written accents show you where the stress falls:

• μαζική → ma-zi-KI
• ωρίμανση → o-RI-man-si
• αρχίζει → ar-HI-zi
• μετά → me-TA
• αυτόλυση → af-TO-li-si

A few useful pronunciation notes:

• χ in αρχίζει is not like English ch in chair. It is a throat sound, like the h-type sound in German Bach.
• υ in αυτόλυση here sounds like i in Modern Greek.
• αι would sound like e, but this sentence does not contain that combination.

In Modern Greek, μετά most commonly means after when followed by a noun phrase in the accusative:

• μετά την αυτόλυση = after the autolysis

Be careful, though: μετά can also appear in other expressions, and older Greek used different case patterns. But for normal Modern Greek usage, you can safely learn:

• μετά + accusative = after

Not necessarily. Greek often allows more than one natural wording, depending on context and style.

For example, if the meaning is technical, scientific, or process-based, Η μαζική ωρίμανση αρχίζει μετά την αυτόλυση is perfectly normal.

But Greek could sometimes express a similar idea with different vocabulary or a different word order, depending on what exactly mass maturation means in context.

So for learning purposes, the main takeaway is the grammar of this sentence:

• Η μαζική ωρίμανση = subject
• αρχίζει = present tense verb, 3rd person singular
• μετά την αυτόλυση = prepositional phrase with accusative

The sentence follows a very common Greek pattern:

Subject + Verb + Prepositional phrase

Broken down:

• Η μαζική ωρίμανση = subject
• αρχίζει = verb
• μετά την αυτόλυση = time-related prepositional phrase

So if you want to build similar sentences, you can copy this structure:

• Η διαδικασία αρχίζει μετά το στάδιο αυτό.
• Η ζύμωση αρχίζει μετά την ανάμιξη.

This makes the sentence a useful model for technical or academic Greek.