A bola está no jardim.

Here a means the, not a/an.

In Portuguese, a can be:

• the feminine singular definite article = the
• also the preposition to in other contexts

In A bola está no jardim, a is the article that goes with bola, because bola is a feminine singular noun.

So:

• a bola = the ball
• uma bola = a ball

That means:

• A bola está no jardim. = The ball is in the garden.
• Uma bola está no jardim. = A ball is in the garden.

Yes. Bola is a feminine noun in Portuguese.

That is why it uses feminine forms like:

• a bola = the ball
• uma bola = a ball

Grammatical gender in Portuguese is a property of the noun, and other words often have to match it. This does not mean the object itself is biologically female. It is just a grammar category.

A learner should get used to learning nouns together with their article:

• a bola
• o jardim

That makes it easier to remember gender.

Portuguese has two main verbs for to be:

• ser → used for identity, permanent characteristics, definitions, origin, time, etc.
• estar → used for location, condition, temporary states

In this sentence, the ball is being located somewhere, so Portuguese uses estar:

• A bola está no jardim. = The ball is in the garden.

You would not normally say A bola é no jardim here.

A very useful rule for beginners is:

• location of people or things → usually estar

Examples:

• Estou em casa. = I am at home.
• O livro está na mesa. = The book is on the table.
• As crianças estão no parque. = The children are in the park.

Está is the third person singular form of estar in the present tense.

Conjugation of estar in the present:

• eu estou
• você / ele / ela está
• nós estamos
• vocês / eles / elas estão

Since a bola is singular, Portuguese uses está:

• A bola está...

If the subject were plural, you would use estão:

• As bolas estão no jardim. = The balls are in the garden.

No is a contraction of:

• em
  • o = no

So:

• em = in / on / at
• o jardim = the garden
• no jardim = in the garden

Portuguese normally contracts these forms, so em o jardim sounds unnatural or incorrect in standard usage.

Common contractions with em are:

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

Examples:

• no jardim = in the garden
• na casa = in the house
• nos carros = in the cars
• nas escolas = in the schools

In this sentence, jardim appears as o jardim, so the full idea is in the garden.

Portuguese uses articles very frequently, often more frequently than English. Here the article is completely natural:

• o jardim = the garden
• no jardim = in the garden

If you removed the article and said em jardim, that would usually sound wrong in this context.

So the structure is:

• A bola = the ball
• está = is
• no jardim = in the garden

Normally, no.

The natural form is:

• A bola está no jardim.

Why?

1. em o contracts to no
2. jardim here normally needs the article o

So:

• em o jardim → no jardim
• em jardim → usually not natural here

A beginner-safe rule is: when you have em + o/a/os/as, use the contracted forms:

• no
• na
• nos
• nas

Yes, this sentence has a very familiar word order for an English speaker:

• A bola = subject
• está = verb
• no jardim = location phrase

So it follows the pattern:

• Subject + verb + place

That is one reason this sentence is beginner-friendly.

However, Portuguese can sometimes change word order for emphasis, but the neutral, standard form here is exactly what you see:

• A bola está no jardim.

The accent mark in está is important.

It shows the stressed syllable and helps distinguish the correct written form. In Brazilian Portuguese, está is pronounced with stress on the last syllable:

• es-TÁ

The accent is part of the standard spelling, so you should write it.

A useful habit is to memorize the common forms with accents exactly as they are written:

• está
• estão
• você
• também

Even if people sometimes omit accents when texting casually, in correct writing you should include them.

In Brazilian Portuguese, jardim is pronounced approximately like zhar-JEEN, though that spelling is only a rough guide.

A few pronunciation points:

• j in Portuguese sounds like the s in measure or the zh sound
• the stress is on the second syllable: jar-DIM
• the final im in Brazilian Portuguese has a nasal sound

So an English speaker should avoid pronouncing the j like English j in job.

A rough beginner approximation:

• zhar-DJEEN or zhar-JEEN

Not perfect, but closer than an English-style jar-dim.

You make the subject plural, and the verb must agree with it.

Singular:

• A bola está no jardim.

Plural:

• As bolas estão no jardim.

Changes:

• a → as
• bola → bolas
• está → estão

Notice that no jardim stays the same because there is still just one garden.

If the garden were plural too, then it would change:

• As bolas estão nos jardins. = The balls are in the gardens.

Not for this meaning.

Tem means has / there is / there are in many everyday Brazilian Portuguese contexts, but it does not replace está when you want to say where a specific thing is.

So:

• A bola está no jardim. = The ball is in the garden.

But:

• Tem uma bola no jardim. = There is a ball in the garden.

These are different ideas:

• A bola está no jardim. → talks about the location of the ball
• Tem uma bola no jardim. → says that there is a ball in the garden

Both are useful, but they are not interchangeable.