Η συνάντηση αρχίζει στις εννέα.

Η is the feminine singular definite article, meaning the.

It is used because συνάντηση (meeting) is a feminine singular noun, so the article has to match it:

• η συνάντηση = the meeting

Greek articles change for gender, number, and case, unlike English the, which always stays the same.

Η συνάντηση is in the nominative case because it is the subject of the sentence: it is the thing that begins.

So in:

• Η συνάντηση αρχίζει...

the meeting is doing the action, so Greek uses the nominative form.

Αρχίζει is the third person singular form of the verb αρχίζω (to begin / to start) in the present tense.

That means it matches η συνάντηση (the meeting), which is singular:

• εγώ αρχίζω = I begin
• εσύ αρχίζεις = you begin
• αυτός/αυτή/αυτό αρχίζει = he/she/it begins

Here, η συνάντηση is grammatically treated like she/it, so Greek uses αρχίζει.

Greek, like English, often uses the present tense for schedules, timetables, and fixed events.

So:

• Η συνάντηση αρχίζει στις εννέα.

works like English:

• The meeting starts at nine.

Even though the meeting may happen later, the present tense sounds natural because it refers to a planned event.

Στις means at when talking about clock time.

So:

• στις εννέα = at nine

It is the normal way to introduce an hour in Greek.

Στις is historically and practically the combination of:

• σε = in / at / to
• τις = the (feminine plural accusative)

With clock time, Greek normally uses this fixed expression:

• στις + hour

For example:

• στις πέντε = at five
• στις οκτώ = at eight
• στις εννέα = at nine

So even if you learn σε first as a preposition, with time you will usually see στις.

Εννέα means nine, and in this kind of expression it stays the same.

Greek cardinal numbers like εννέα are commonly used directly for telling time:

• στις εννέα = at nine
• στις δέκα = at ten

So you do not need to learn a special separate form here.

Yes, in normal use it means at nine or at nine o’clock.

Greek often does not need a separate word for o’clock in everyday sentences. The time expression alone is enough.

If the context is clear, στις εννέα naturally means the hour, not the number in some abstract sense.

Yes, Greek word order is more flexible than English, although Η συνάντηση αρχίζει στις εννέα is the most neutral and natural version.

You may also hear:

• Στις εννέα αρχίζει η συνάντηση.

This puts more emphasis on the time: At nine, the meeting begins.

Because Greek marks grammatical relationships through endings and articles more clearly than English, word order can move around more freely.

A rough pronunciation is:

ee see-NAN-tee-see ar-khee-ZEE stis e-nya

A few helpful points:

• η sounds like ee
• συνάντηση has the stress on νά
• αρχίζει has the stress on the last-but-one syllable: ζί
• εννέα is pronounced roughly e-nya

The written accent marks show you where the stress goes:

• συνάντηση
• αρχίζει
• εννέα

Both can often mean starts / begins, but they are not always identical in tone.

• αρχίζει is the more direct equivalent of begins / starts
• ξεκινάει often means starts off / sets off / gets started

For a meeting, αρχίζει is very natural:

• Η συνάντηση αρχίζει στις εννέα.

You may also hear:

• Η συνάντηση ξεκινάει στις εννέα.

That is also common in everyday Greek, especially spoken Greek.

Greek often drops subject pronouns like he, she, or it, because the verb ending already gives information. But in this sentence, η συνάντηση is not a pronoun: it is the actual noun the meeting, so it is normally included.

You would not usually just say:

• Αρχίζει στις εννέα.

unless the context already makes it completely clear what begins at nine.

So yes, Greek can leave out pronouns, but here the noun phrase η συνάντηση is useful and natural.