Minha irmã deixa a moto na vaga de garagem.

Because minha has to agree with irmã, the thing being possessed.

• irmã = sister, a feminine singular noun
• minha = my for a feminine singular noun
• meu would be used with a masculine singular noun, like meu irmão = my brother

In Portuguese, possessives agree with the noun that follows them.

In Brazilian Portuguese, both versions are possible:

• Minha irmã deixa a moto...
• A minha irmã deixa a moto...

Both can mean my sister leaves the motorcycle...

In Brazil, omitting the article before a possessive is very common, especially in more neutral or written-style sentences. Using the article can sound a little more conversational in many contexts. So minha irmã is completely natural.

Deixa is the third-person singular present tense of deixar.

So:

• eu deixo = I leave
• você/ele/ela deixa = you/he/she leaves
• minha irmã deixa = my sister leaves

Since minha irmã is third-person singular, deixa is the correct form.

Here, deixar means to leave something somewhere.

So deixa a moto na vaga de garagem means that she leaves the motorcycle in the parking spot / garage space.

But deixar can also mean other things depending on context, such as:

• to let / allow
  
  • Ela deixa o filho sair. = She lets her son go out.
• to leave behind
  
  • Deixei o celular em casa. = I left my phone at home.

In this sentence, the location na vaga de garagem makes the leave/park meaning clear.

Portuguese often uses definite articles more than English does.

So a moto literally means the motorcycle, but in many contexts English would simply say the motorcycle or sometimes just imply it naturally.

Here, a moto suggests a specific motorcycle, probably one already known from context, such as her motorcycle or the motorcycle we are talking about.

Also, moto is feminine, so the article is a.

Na is a contraction of:

• em = in / on / at
• a = the

So:

• em + a = na

That is why:

• na vaga = in the parking space / in the spot

This kind of contraction is very common in Portuguese:

• no = em + o
• na = em + a
• nos = em + os
• nas = em + as

Because de garagem works like a noun modifier: it describes what kind of space it is.

• vaga de garagem = garage parking space / parking spot
• literally, space of garage, but more naturally garage space or parking spot

If you said vaga da garagem, that would usually sound more like the garage’s spot or the spot of the garage, referring to a specific garage in a more possessive way.

So:

• vaga de garagem = the normal, general expression
• vaga da garagem = more specific and less likely here

Yes, but the meaning changes slightly.

• na vaga de garagem = in the parking spot / in the garage space
• na garagem = in the garage

The original sentence is more specific. It tells you she leaves the motorcycle in the designated parking space, not just somewhere in the garage.

Yes. Moto is the common everyday word for motorcycle in Brazilian Portuguese.

• moto = very common, normal in speech
• motocicleta = more formal or technical

So this sentence sounds natural and everyday with moto.

Usually, a sentence like this is understood as a habit, a routine, or a general fact:

• Minha irmã deixa a moto na vaga de garagem.
• My sister leaves the motorcycle in the parking spot.

That often sounds like something she normally does.

Depending on context, the present tense in Portuguese can also describe something happening now, but without context, the habitual reading is very natural.

Yes. This is the most neutral and standard word order:

• Minha irmã = subject
• deixa = verb
• a moto = direct object
• na vaga de garagem = location

So the pattern is basically:

Subject + Verb + Object + Place

That is the most straightforward way to say it.

The hardest part for many English speakers is the ã.

A helpful approximation is:

• irmã ≈ eer-MAHN, but with the ending nasalized and without a strong final n

More accurately in Brazilian Portuguese, it is roughly:

• [iʁˈmɐ̃]

A few pronunciation notes:

• ir starts with a sound like eer
• the r in many Brazilian accents is not like the English r
• ã is nasal, so the sound comes partly through the nose

So the final syllable should not sound like a plain ma. It should sound nasal: mã.

Because they are functioning differently in the sentence.

• a moto refers to a specific motorcycle, so it takes the definite article
• de garagem is not referring to the garage as a separate specific object; it is part of the fixed expression vaga de garagem, meaning garage space / parking space

So:

• a moto = a specific thing
• vaga de garagem = a type of space

That is why the article appears with moto but not before garagem.