Los fuegos artificiales empiezan a las diez.

In Spanish, fireworks is commonly expressed as fuegos artificiales, which is a fixed plural expression.

• fuegos = fires
• artificiales = artificial

Even though the literal meaning looks strange in English, together they simply mean fireworks. Spanish usually treats this as a plural noun, so you say:

• Los fuegos artificiales son bonitos.
• Los fuegos artificiales empiezan a las diez.

You would not normally translate English fireworks word-for-word as a single Spanish word here.

Spanish often uses the definite article much more than English does. So los fuegos artificiales is the natural way to say the fireworks or sometimes simply fireworks in a general event context.

In English, we might say:

• Fireworks start at ten.

But in Spanish, it is very common to include the article:

• Los fuegos artificiales empiezan a las diez.

Leaving out los would usually sound less natural here.

Because adjectives in Spanish must agree with the noun they describe.

Here:

• fuegos is masculine plural
• so the adjective must also be masculine plural: artificiales

Compare:

• fuego artificial = a firework
• fuegos artificiales = fireworks

This is standard adjective agreement in Spanish.

Because the subject is plural: los fuegos artificiales.

The verb empezar must agree with the subject:

• empieza = he/she/it starts
• empiezan = they start

Since the fireworks is plural, Spanish uses empiezan.

It comes from the verb empezar, which means to begin or to start.

This is the present tense form:

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

Notice the stem change e → ie in most forms, including empiezan.

Because empezar is a stem-changing verb in the present tense. The e in the stem changes to ie in most forms.

Examples:

• empiezo
• empiezas
• empieza
• empezamos
• empezáis
• empiezan

So ellos/ellas empiezan is exactly what you expect from this pattern.

In Spanish, clock times are normally introduced with a la or a las.

• a la una = at one o’clock
• a las dos = at two o’clock
• a las diez = at ten o’clock

You use a la only with one, because una is singular. For all other hours, use a las.

So:

• Empieza a la una.
• Empiezan a las diez.

By itself, a las diez just means at ten o’clock. The sentence does not specify morning or night.

If the context is fireworks, a learner would usually assume 10:00 p.m., because fireworks are typically at night. But grammatically, the sentence alone does not force that meaning.

If you want to be explicit, you could say:

• a las diez de la mañana = at 10 a.m.
• a las diez de la noche = at 10 p.m.

Yes. In Spanish, the present tense is often used to talk about scheduled future events, just like in English.

So:

• Los fuegos artificiales empiezan a las diez.

can mean:

• The fireworks start at ten.

This is very natural for timetables, programmes, events, and planned actions.

Yes. Los fuegos artificiales van a empezar a las diez is also correct.

There is a small difference in feel:

• empiezan a las diez = very natural for schedules, programmes, and official event times
• van a empezar a las diez = also natural, sometimes a bit more like are going to start at ten

In this context, both work well, but the original sentence sounds especially natural for an event schedule.

Yes, almost. You could also say:

• Los fuegos artificiales comienzan a las diez.

Both empezar and comenzar mean to start / to begin.

In many everyday situations, empezar is a little more common in speech, while comenzar can sound slightly more formal, depending on context. But both are completely correct here.

A broad pronunciation guide would be:

lohs FWEH-gohs ar-tee-fee-thya-LEHS em-PYEH-than ah lahs DYEHTH

In much of Spain:

• z in empiezan and diez is pronounced like th in think
• c before e/i would also have that sound in many parts of Spain
• ll is often pronounced like an English y sound, though there is regional variation

A more neutral spelling-based guide is:

lohs FWEH-gohs ar-tee-fee-thya-LEHS em-PYEH-than ah lahs DYEHTH

If you are learning Peninsular Spanish, that th sound is normal.

Yes, but the meaning changes slightly.

• un fuego artificial = a firework
• los fuegos artificiales = the fireworks / fireworks

So if you are talking about the whole display, Spanish normally uses the plural:

• Los fuegos artificiales empiezan a las diez.

If you mean just one firework:

• El fuego artificial explota en el aire.

But for the event as a whole, the plural is much more natural.

The word order is very straightforward:

• Los fuegos artificiales = subject
• empiezan = verb
• a las diez = time expression

So it follows a normal pattern like:

Subject + verb + time

This is very similar to English:

• The fireworks start at ten.

Spanish can sometimes move elements around for emphasis, but this neutral order is the most common here.