Τα φώτα ανάβουν ταυτόχρονα.

Τα is the definite article for a neuter plural noun.

So:

• τα φώτα = the lights

Greek articles change for gender, number, and case, so learners need to pay more attention to them than in English. Here τα matches φώτα.

A useful detail: τα is the same form for both nominative and accusative neuter plural.

The singular is το φως = the light.

The plural is τα φώτα = the lights.

This is a noun with an irregular-looking plural, so it is best learned as a pair:

• το φως
• τα φώτα

In everyday Greek, φώτα often refers to actual lights, lamps, or lighting.

Ανάβουν is the 3rd person plural present tense of ανάβω.

So it corresponds to they light / they turn on / they come on, depending on context.

Why plural? Because the subject is τα φώτα, which is plural.

A helpful breakdown:

• ανάβω = I light / I turn on
• ανάβεις = you light / turn on
• ανάβει = he/she/it lights / turns on
• ανάβουν = they light / turn on / come on

Because in this sentence the verb is being used intransitively.

Greek often uses the same active verb both:

• transitively: Ανάβω τα φώτα = I turn on the lights
• intransitively: Τα φώτα ανάβουν = The lights come on / light up

So here the lights are not being turned on by someone mentioned in the sentence; the sentence simply says that the lights themselves come on.

We know from the meaning and the way the verb is being used.

A tricky point for learners is that with neuter plural nouns, the nominative and accusative forms are often identical. So τα φώτα could look like either the lights as a subject or the lights as an object.

But here ανάβουν is being used without an object, so τα φώτα must be the subject:

• Τα φώτα ανάβουν = The lights come on

If it were transitive, you would expect another subject, for example:

• Εγώ ανάβω τα φώτα = I turn on the lights

Ταυτόχρονα is an adverb.

It means simultaneously or at the same time.

It describes how the lights come on.

Unlike nouns and articles, an adverb like ταυτόχρονα does not change form here for gender, number, or case.

Yes. Greek word order is often more flexible than English word order.

The sentence you have is a very natural, neutral version:

• Τα φώτα ανάβουν ταυτόχρονα.

But Greek can move things around for emphasis, for example:

• Ταυτόχρονα ανάβουν τα φώτα.
• Ανάβουν τα φώτα ταυτόχρονα.

These versions are still understandable, but they may sound more marked or may emphasize a different part of the message. The original order is a good standard pattern for learners.

It can mean either one, depending on context.

Greek present tense often covers both:

• an action happening now
• a habitual or general action

So this sentence could mean:

• The lights are coming on simultaneously
• The lights come on simultaneously

English often forces you to choose between simple present and present progressive, but Greek present tense is more flexible.

A rough English-friendly pronunciation is:

ta FO-ta a-NA-voon taf-TO-khro-na

Stress falls on:

• φώτα → FO
• ανάβουν → NA
• ταυτόχρονα → TO

A few pronunciation notes:

• φ sounds like English f
• ου sounds like oo in food
• χ is not English ch; it is the throat sound heard in Scottish loch or German Bach
• in ταυτόχρονα, the αυ is pronounced af here, because it comes before the voiceless consonant τ

So ταυτόχρονα sounds roughly like taf-TO-khro-na.