A praça onde minha sobrinha brinca fica perto da ponte velha.

Onde means where.

In this sentence, onde introduces a clause that describes a praça:

• A praça onde minha sobrinha brinca = The square/plaza where my niece plays

It is used because praça is a place, and onde is commonly used to refer back to places.

A more formal alternative would be na qual:

• A praça na qual minha sobrinha brinca...

But in everyday Brazilian Portuguese, onde is much more natural.

Portuguese uses definite articles much more often than English.

So where English might say:

• The square
• the old bridge

Portuguese naturally says:

• a praça
• a ponte velha

In da ponte velha, the da includes the article:

• de + a = da

So:

• perto da ponte velha = near the old bridge

This is very normal in Portuguese.

Here, fica means something like:

• is located
• is situated
• lies

So:

• A praça ... fica perto da ponte velha
  = The square ... is near the old bridge

Although ficar can sometimes mean to stay, in location sentences it very often means to be located.

For example:

• O banco fica na esquina. = The bank is on the corner.
• Minha casa fica longe. = My house is far away.

So in this sentence, fica is about location, not staying.

The basic expression is perto de = near.

When de comes before a, it contracts:

• de + a = da

So:

• perto de a ponte velha becomes perto da ponte velha

This contraction is required in normal Portuguese.

Other examples:

• perto do mercado = near the market
  (de + o = do)
• perto da escola = near the school

Brinca is the present tense of brincar for ele/ela/você.

Here it most naturally means:

• plays
• or usually plays

So:

• minha sobrinha brinca = my niece plays

In Portuguese, the simple present can cover both:

• habitual actions (plays)
• and sometimes present activity depending on context

If you specifically wanted is playing right now, Portuguese often uses:

• está brincando

But in this sentence, brinca sounds like a general fact: this is the square where she plays.

Portuguese does not need a separate word like English that here, because onde already connects the noun to the clause.

Compare:

• A praça onde minha sobrinha brinca
• literally: The square where my niece plays

The word onde does the linking job by itself.

If the noun were not a place, Portuguese would often use que instead:

• O livro que eu comprei = The book that I bought

But because praça is a place, onde is the natural choice.

In Portuguese, adjectives usually come after the noun:

• ponte velha = old bridge

That is the neutral, standard order.

If you put velha before the noun, it can sound more literary, emotional, or slightly different in nuance depending on context:

• a velha ponte

This can still mean the old bridge, but it may feel more descriptive or stylistic rather than just neutral factual description.

So for ordinary everyday speech, a ponte velha is the most straightforward choice.

Good question. In Brazilian Portuguese, possessives can appear with or without the definite article, depending on region, style, and context.

So both of these are possible:

• minha sobrinha
• a minha sobrinha

In Brazil, omitting the article is very common, especially in simple sentences and everyday speech.

So:

• onde minha sobrinha brinca
• onde a minha sobrinha brinca

Both are understandable and correct. The version without the article sounds very natural in Brazilian Portuguese.

Praça usually means a public square or plaza.

Depending on the place, it may also feel a bit like a small public open area where people sit, walk, and children play. In some contexts, English speakers might even think of it as a small park-like square, but praça is not exactly the same as parque.

So possible translations depend on context:

• square
• plaza
• sometimes a small public square/park area

In this sentence, because the niece plays there, it may feel like a public square with space for children.

Sobrinha means niece.

It comes from:

• sobrinho = nephew
• sobrinha = niece

Here, -a marks the feminine form.

Be careful not to confuse this with the diminutive ending -inha that appears in other words. In sobrinha, the word is simply the normal feminine form of sobrinho; it is not necessarily a “little niece.”

So:

• meu sobrinho = my nephew
• minha sobrinha = my niece

In Brazilian Portuguese, praça is pronounced roughly like PRAH-sa.

A few helpful points:

• ç sounds like s
• the first syllable pra is stressed
• the final a is an unstressed a sound

So:

• praça ≈ PRAH-sa

And a few other words from the sentence:

• onde ≈ ON-jee or ON-djee (varies by accent)
• sobrinha ≈ so-BREEN-ya
• brinca ≈ BRING-ka
• ponte ≈ PON-chee or PON-tee depending on accent
• velha ≈ VEHL-ya

These are only approximations, but they can help an English speaker get started.