La reunión empieza a las siete.

Empieza is the conjugated form of the verb empezar for él/ella/usted. Here, the subject is la reunión, which is third-person singular, so you need empieza.

Also, empezar is a stem-changing verb in the present tense: e → ie in stressed forms.

• yo empiezo
• tú empiezas
• él/ella/usted empieza
• nosotros empezamos
• vosotros empezáis
• ellos/ellas/ustedes empiezan

So la reunión empieza is grammatically correct.

Spanish often uses the present tense for scheduled future events, just like English does in sentences such as The meeting starts at seven. So La reunión empieza a las siete is a very natural way to talk about a future timetable or arrangement.

You could also say La reunión va a empezar a las siete or La reunión empezará a las siete, but the simple present is very common here.

Spanish uses the preposition a with clock times, where English uses at. So:

• a las dos = at two
• a las siete = at seven
• a las nueve = at nine

So a las siete is the normal way to say at seven.

Spanish treats most clock times as plural, so it uses las with all hours except one o’clock.

• a la una = at one
• a las dos
• a las siete
• a las once

So siete takes las, not la.

Not always. A las siete can mean either at 7 a.m. or at 7 p.m., and the context often makes it clear.

If you want to be specific, you can add:

• a las siete de la mañana = at 7 in the morning
• a las siete de la tarde = at 7 in the evening
• a las siete de la noche = at 7 at night

Yes. Empieza and comienza both mean starts/begins and are usually interchangeable in a sentence like this:

• La reunión empieza a las siete
• La reunión comienza a las siete

Empezar is often a little more everyday and common in casual speech, but both are correct.

Yes. Spanish word order is more flexible than English word order. La reunión empieza a las siete is a very neutral sentence. Empieza la reunión a las siete is also correct, but it may shift the emphasis slightly.

For example, Empieza la reunión a las siete can sound a bit more like you are focusing on the fact that it starts at seven.

The written accent in reunión shows that the stress falls on the last syllable: reunión. In Spanish spelling, a word ending in n, s, or a vowel would normally be stressed on the second-to-last syllable unless an accent mark shows otherwise. The accent tells you not to stress it that way.

A rough pronunciation is reh-oo-NYON, with the stress on the end.