O canteiro fica perto da horta.

Both nouns are grammatical nouns with fixed gender:

• canteiro is masculine → o canteiro
• horta is feminine → a horta

In the sentence, da is a contraction of:

• de + a = da

So perto da horta literally contains de + a horta.

This is very common in Portuguese:

• do = de + o
• da = de + a
• dos = de + os
• das = de + as

Because perto normally takes the preposition de.

So the pattern is:

• perto de + noun

Examples:

• perto da horta
• perto do jardim
• perto de casa

Since horta uses the article a, de + a becomes da:

• perto de a horta → perto da horta

In Portuguese, ficar is often used to say where something is located or situated.

So O canteiro fica perto da horta means that the flower bed/garden bed is located near the vegetable garden.

Compare:

• é = expresses identity or a defining characteristic
• está = often describes a temporary state or position
• fica = often means is situated / lies / is located

With places and physical location, ficar is very natural:

• A escola fica perto da estação.
• A casa fica no fim da rua.

Here, canteiro usually means a garden bed, flower bed, or plant bed: a prepared patch of soil where things are planted.

Depending on context, canteiro can refer to:

• a flower bed
• a raised bed
• a planting bed in a garden or vegetable plot

So in this sentence, it most likely refers to a planted area near the horta.

They are related, but not the same:

• canteiro = a specific planted bed or section of soil
• horta = a vegetable garden or kitchen garden as a whole

So the idea is something like:

• the bed is near the vegetable garden

A horta may contain several canteiros.

Usually, with this sentence, perto da horta sounds more natural because you are talking about a specific vegetable garden.

• perto da horta = near the vegetable garden
• perto de uma horta = near a vegetable garden

Perto de horta without an article is not the normal choice here.

In Portuguese, the h at the beginning of a word is silent.

So horta is pronounced roughly like OR-ta.

A few pronunciation notes for European Portuguese:

• h is silent
• the r in horta is a tapped or slightly stronger r, depending on speaker and position
• the final a is usually a reduced unstressed vowel in European Portuguese, not a strong English ah

A useful approximation is:

• canteiro ≈ kun-TAY-roo / kɐ̃n-TEI-ru

A few things to notice:

• the first syllable is unstressed and reduced in European Portuguese
• ei sounds like ay
• the final o in European Portuguese is often reduced, closer to u than a full English oh

You do not need to pronounce it exactly like English spelling suggests.

This is the normal, neutral word order:

• subject + verb + location expression

So:

• O canteiro fica perto da horta.

You can change the order for emphasis, but it is less neutral:

• Perto da horta fica o canteiro.

That sounds more marked or literary. For everyday speech, the original order is the safest choice.

You change the article, noun, and verb as needed.

For example:

• Os canteiros ficam perto da horta.
  = The garden beds are near the vegetable garden.

If both nouns are plural:

• Os canteiros ficam perto das hortas.

Notice:

• o → os
• canteiro → canteiros
• fica → ficam
• da → das when the following noun is feminine plural

Yes. Próximo de can often be used with a very similar meaning to perto de.

So these are both possible:

• O canteiro fica perto da horta.
• O canteiro fica próximo da horta.

In everyday language, perto is very common and straightforward. Próximo may sound slightly more formal, depending on context.

In this sentence, perto functions as part of a location expression, not as a normal descriptive adjective before a noun.

It works in the pattern:

• ficar + perto de + noun

So it behaves more like near in English:

• is near the garden

You should learn it as a chunk:

• perto de
• longe de

Examples:

• A casa fica perto da escola.
• A aldeia fica longe da cidade.