As luzes começaram a piscar.

As is the feminine plural definite article, meaning the.

• a = the (feminine singular)
• as = the (feminine plural)
• o = the (masculine singular)
• os = the (masculine plural)

Since luzes means lights and is a plural feminine noun, it takes as:

• a luz = the light
• as luzes = the lights

Because luz is a noun ending in -z, and its plural is formed by changing -z to -zes:

• luz → luzes

This is a normal plural pattern in Portuguese for many words ending in -z.

Yes, luz is feminine.

You usually learn a noun’s gender together with its article:

• a luz
• as luzes

There is not always a simple rule based on the ending, so it is best to memorize nouns with their article.

Because the subject is plural: as luzes.

The verb has to agree with the subject:

• A luz começou a piscar. = The light started blinking.
• As luzes começaram a piscar. = The lights started blinking.

So começaram is the 3rd person plural form of começar in the past.

Começaram is the pretérito perfeito in Portuguese, often called the simple past in English explanations.

It is used for a completed event in the past. Here it means that, at some point in the past, the lights started blinking.

From the verb começar:

• eu comecei
• tu começaste
• ele/ela começou
• nós começámos (European Portuguese spelling with accent)
• vocês/eles/elas começaram

The ç is called c cedilha.

It shows that the c is pronounced like s, not like k.

So:

• começar sounds with an s sound in the middle
• without the cedilla, comecar would suggest a different pronunciation and is not correct spelling

This happens because of Portuguese spelling rules before a, o, and u.

After começar, Portuguese normally uses a + infinitive:

• começar a fazer
• começar a falar
• começar a chover
• começar a piscar

So começaram a piscar literally means started to blink.

This structure is very common in European Portuguese.

No, that would be incorrect here.

With começar, you normally say:

• começar a + infinitive

So the correct form is:

• começaram a piscar

not

• começaram piscar

Because after começar, Portuguese uses the infinitive, not the gerund, in this structure:

• começar a piscar = to start blinking

Also, in European Portuguese, a + infinitive is very common in places where English uses -ing forms.

So this sentence follows a very standard Portuguese pattern.

No. Piscar can be used for both:

• eyes blinking
• lights flashing/blinking

Examples:

• Ela piscou os olhos. = She blinked her eyes.
• As luzes estavam a piscar. = The lights were blinking.

So using piscar for lights is completely natural.

Piscar by itself can mean to blink or to flash, depending on the subject.

• If the subject is a person, it often means to blink
• If the subject is a light, it means to flash/blink

Piscar os olhos is more explicit and means to blink one’s eyes.

So in your sentence, because the subject is as luzes, piscar clearly means to flash/blink.

Yes, but the meaning changes slightly.

• As luzes começaram a piscar. = The lights started blinking.
• As luzes piscaram. = The lights blinked/flashed.

The first sentence focuses on the beginning of the action. The second just says the action happened.

The dictionary forms are:

• começar = to begin / to start
• piscar = to blink / to flash

In the sentence:

• começaram is a conjugated form of começar
• piscar stays in the infinitive because it comes after a

The singular version is:

• A luz começou a piscar.

Changes:

• as → a
• luzes → luz
• começaram → começou

The word order is very normal for Portuguese:

• As luzes = subject
• começaram = main verb
• a piscar = verb complement

So it follows the same basic pattern as English:

• The lights / started / blinking

A rough guide for an English speaker would be something like:

azh LOO-zesh kuh-meh-SAH-rung uh pish-KAR

A few useful points:

• as often sounds like azh in connected European Portuguese speech
• luzes has a soft z sound between vowels
• ç in começaram sounds like s
• final unstressed vowels are often reduced in European Portuguese
• piscar has stress on the last syllable: pis-CAR

This is only an approximation, but it can help at first.

In European Portuguese, pronunciation often changes in connected speech.

The final -s of as can sound like:

• sh
• zh

depending on what follows.

Before a voiced sound, it often becomes zh. Since luzes begins with l, many speakers pronounce as luzes approximately like azh luzes.

So the spelling stays as, but the sound changes naturally in speech.

Yes, very natural.

As luzes começaram a piscar is exactly the kind of sentence a native speaker in Portugal would say for lights that suddenly start flashing or blinking. It sounds fully idiomatic and normal.