A luz ainda está ligada.

In Portuguese, it is very common to use the definite article with nouns when English would often leave it out.

So a luz means the light. In a sentence like this, Portuguese normally uses the article because it is referring to a specific light or the light in a particular place.

• A luz ainda está ligada. = The light is still on.

If you said just Luz ainda está ligada, it would sound unnatural in normal speech.

Luz is a feminine noun in Portuguese, so it takes feminine words with it:

• a luz
• ligada (not ligado)

This is something you usually just have to learn with the noun. The ending does not always tell you the gender. Even though luz does not end in -a, it is still feminine.

Here, ainda means still.

So:

• ainda está ligada = is still on

It shows that the situation continues. The light was on before, and it remains on now.

Depending on context, ainda can also mean yet or even, but in this sentence the natural meaning is still.

In Portuguese, adverbs like ainda are often placed before the verb.

So:

• A luz ainda está ligada.

is the normal, natural order.

You may also hear slightly different word orders in some contexts, but this placement is the standard one learners should use first.

Portuguese has two main verbs for to be: ser and estar.

Here it uses estar because the light being on is a state or condition, not a permanent characteristic.

• está ligada = is on
• é ligada would not mean the same thing and would sound wrong here

So when talking about something being turned on or off, Portuguese normally uses estar:

• A TV está ligada.
• O computador está desligado.

Literally, ligada comes from the verb ligar, which can mean to turn on, to connect, or to switch on, depending on context.

In this sentence, está ligada means is on.

So the structure is roughly:

• estar + ligado/ligada = to be on
• estar + desligado/desligada = to be off

Because luz is feminine, it becomes ligada.

Because adjectives and many past-participle-like forms in Portuguese agree with the noun they describe.

• a luz is feminine singular
• so it takes ligada

Compare:

• A luz está ligada.
• O computador está ligado.

Same idea, but the ending changes to match the noun.

Yes. That is very natural too.

Both of these can mean The light is still on:

• A luz ainda está ligada.
• A luz ainda está acesa.

There is a slight nuance:

• ligada focuses more on the light being switched on
• acesa focuses more on the light being lit

In everyday Brazilian Portuguese, both are common and correct.

No. Ligado/ligada is used for many devices and things that can be on:

• A TV está ligada. = The TV is on.
• O rádio está ligado. = The radio is on.
• O celular está ligado. = The cell phone is on.

So this pattern is very useful beyond just luz.

The opposite is:

• A luz ainda está desligada. = The light is still off.

For lights specifically, you can also hear:

• A luz ainda está apagada.

A common contrast is:

• ligada / desligada = on / off
• acesa / apagada = lit / unlit, on / off (especially for lights)

In Brazilian Portuguese, está is pronounced approximately like eh-STAH, with the stress on the second syllable.

A few notes:

• the es- at the start sounds like ehs
• the final á is a stressed ah sound
• in normal speech, some speakers may reduce the first syllable a little, but learners should clearly say es-TÁ

So the sentence rhythm is roughly:

• A LUZ ain-DA es-TÁ li-GA-da

Yes, sometimes, if the context is clear.

For example, if everyone is talking about the light, a speaker might say:

• Ainda está ligada. = It’s still on.

Portuguese often omits things that are understood from context. But for learners, using the full sentence:

• A luz ainda está ligada.

is safer and clearer.