La réunion commence à huit heures et quart.

In French, nouns usually need an article. La réunion means the meeting. If you said just réunion by itself, it would usually sound incomplete.

Also, réunion is a feminine noun, so it takes la in the singular:

• la réunion = the meeting
• une réunion = a meeting

A useful pattern: many nouns ending in -ion are feminine, and réunion is one of them.

Because after the subject, French normally uses a conjugated verb, not the infinitive.

The infinitive is commencer = to begin / to start.
But here the subject is la réunion = the meeting, which is third person singular, so in the present tense you use commence:

• je commence = I begin
• tu commences = you begin
• il / elle commence = he / she begins
• la réunion commence = the meeting begins

So commence is the correct present-tense form.

It can mean both. In this sentence, commence is a very natural way to say that something begins at a certain time.

For example:

• Le film commence à neuf heures. = The film begins / starts at nine.
• Le cours commence à dix heures. = The class begins / starts at ten.

So if your translation says begins or starts, both are fine.

French uses à to mean at when giving the time something happens.

So:

• à huit heures = at eight o’clock
• à midi = at noon
• à minuit = at midnight

In this sentence, à introduces the specific time when the meeting begins.

Because French literally says eight hours, so heures is plural after numbers greater than one.

Compare:

• à une heure = at one o’clock
• à deux heures = at two o’clock
• à huit heures = at eight o’clock

So the plural heures is completely normal here.

Et quart means and a quarter, so in time expressions it means quarter past.

So:

• huit heures et quart = quarter past eight / eight fifteen

Other common time expressions are:

• et demie = half past
• moins le quart = quarter to

Examples:

• neuf heures et demie = half past nine
• dix heures moins le quart = quarter to ten

Yes. Both are correct.

• huit heures et quart = eight fifteen / quarter past eight
• huit heures quinze = eight fifteen

Et quart is very common in everyday speech.
Huit heures quinze is also common, and it may feel a little more direct or schedule-like.

In writing, you might also see:

• 8 h 15

So all of these are normal ways to express the same time.

No. The h in heures is silent.

So heures begins with a vowel sound, not an English h sound. That means huit heures flows together smoothly in pronunciation.

Also, the final t in huit is heard here, so huit heures sounds roughly like weet eur, though the real French vowels are different from English.

A rough English guide is ray-yoo-nyon, but that is only approximate.

A few points:

• ré- sounds like ray
• the u in French is not the same as English oo; it is a French front-rounded vowel
• the ending -on is nasal, so it is not pronounced like a full English on

The stress is also not strong the way it is in English. French rhythm is generally flatter and more even.

Because French does not use an article before clock time in this structure. You simply say:

• à huit heures
• à trois heures
• à une heure

So à huit heures et quart is the normal pattern. Adding les would be incorrect here.