eki ha mati no nisi ni aru.

は marks 駅 as the topic of the sentence: as for the station...

So the sentence is structured like:

• 駅は = as for the station
• 町の西にある = it is to the west of the town

Using が would put more focus on 駅 itself, as if identifying it or emphasizing it. In a neutral sentence like this, は is very common because the speaker is simply stating something about the station.

Literally, 町の西 means the town’s west or the west of the town.

Breakdown:

• 町 = town
• の = connects nouns, often like of
• 西 = west

So 町の西 means the west side / western area of the town.

の links two nouns together.

In 町の西, it connects:

• 町 = town
• 西 = west

This creates the meaning the west of the town.

A native English speaker might want to translate の as of, and that works well here. But more generally, の is a very flexible noun-linking particle, not just a strict equivalent of of.

に marks the location where something exists.

In this sentence:

• 町の西に = in/to the west of the town
• ある = exists / is located

So に shows the place where the station is located.

This is very common with ある and いる:

• 学校は駅の前にある。 = The school is in front of the station.
• 先生は教室にいる。 = The teacher is in the classroom.

ある is used for the existence or location of inanimate things.

A station is not alive, so Japanese uses ある, not いる.

• ある = exists / is located there, for things
• いる = exists / is there, for people and animals

So:

• 駅は町の西にある。 = The station is west of the town.
• Not いる, because a station is not a living being.

It can be understood as both, but in this sentence it is most natural to think of it as to be located.

Literally, Japanese often says something like The station exists at the west of the town, but in natural English we say:

• The station is west of the town
• The station is located west of the town

So ある often covers ideas that English expresses with is, there is, or is located.

Japanese does not have articles like a or the.

So 駅 can mean:

• a station
• the station

Which one is meant depends on context.

In this sentence, the meaning is probably the station, because the sentence is talking about a specific station already known in the conversation or situation. But Japanese itself does not mark that with an article.

Japanese verbs normally come at the end of the sentence.

So the basic order here is:

• 駅は = topic
• 町の西に = location
• ある = verb

This is very typical Japanese word order. English says:

• The station is west of the town

Japanese places the verb last:

• As for the station, west of the town it exists

That sounds unnatural in English, but it is normal in Japanese.

Yes. 駅は町の西にあります。 is the polite version.

• ある = plain form
• あります = polite form

The meaning is the same. The choice depends on the situation:

• ある: casual, plain, dictionary form
• あります: polite speech

A textbook might show ある because it is the basic form learners need to know.

Yes. In this sentence, 西 functions as a noun meaning west.

That is why it can appear in a noun phrase:

• 町の西 = the west of the town

Japanese direction words such as 東 (east), 西 (west), 南 (south), and 北 (north) can often behave like nouns.

Yes, in actual translation it often comes out as west of the town.

Japanese 町の西にある is a natural way to express that something is on the western side relative to the town. Depending on context, English may translate it as:

• in the west of the town
• on the west side of the town
• west of the town

The exact English wording can vary, even though the Japanese structure stays the same.

By itself, the sentence does not always make that perfectly precise.

町の西にある generally suggests in the western part of the town or to the west of the town, and context decides which is intended.

If someone wanted to be more specific, Japanese could use other expressions, for example:

• 町の西側にある = it is on the west side of the town
• 町の西方にある = it is to the west of the town

But the original sentence is natural and common, and context usually makes the meaning clear.