kouisitu ha koko desu.

It is usually read こういしつ (kouishitsu).

• 更衣 = changing clothes
• 室 = room

So 更衣室 means changing room or locker room, depending on context.

In this sentence, は is the topic particle, and when は is used as a particle, it is pronounced wa, not ha.

So:

• written: 更衣室 は ここ です
• read aloud: こういしつ わ ここ です

This is one of the first unusual spelling/pronunciation patterns learners meet in Japanese.

は marks the topic of the sentence.

Here, the topic is 更衣室. The sentence is saying something about the changing room:

• As for the changing room, it is here.

Japanese often organizes sentences as topic + comment.

So:

• 更衣室は = as for the changing room
• ここです = it is here

Japanese sentence structure is often different from English.

English says:

• The changing room is here.

Japanese says:

• Changing room + topic marker + here + is

So 更衣室 は ここ です follows a very normal Japanese pattern:

• [topic] は [description] です

This is one of the most common beginner sentence patterns.

ここ means here, meaning a place near the speaker.

Japanese has a basic location set:

• ここ = here
• そこ = there (near the listener)
• あそこ = over there (away from both)
• どこ = where

So in this sentence, ここ tells you the location of the changing room.

です is a polite sentence ending often taught as is / am / are, though it does not work exactly the same as English to be in every situation.

In this sentence, です makes the statement polite and complete:

• ここです = it is here

Without です, the sentence would sound less polite or incomplete in standard speech.

Yes, in a way.

Japanese often leaves out words that are understood from context. After 更衣室は, the listener already knows what the topic is, so Japanese does not need to repeat something like it.

So:

• 更衣室はここです
• literally: As for the changing room, here is
• natural English: The changing room is here

Japanese relies on context much more than English does.

Japanese does not have articles like a, an, or the.

Whether 更衣室 means:

• a changing room
• the changing room
• changing rooms

depends on context.

In this sentence, English usually translates it as the changing room is here, but Japanese itself does not explicitly mark the.

Yes, but the nuance changes.

• 更衣室はここです = As for the changing room, it is here
• 更衣室がここです = The changing room is here / It is the changing room that is here

Using が can sound more like identifying or focusing on the changing room itself, often in contrast to something else.

For a basic neutral statement, は is the more standard choice.

Yes. It is polite because it ends with です.

It is appropriate in many everyday situations, such as:

• answering someone’s question
• giving directions
• speaking to someone you do not know well

A more formal or customer-service-like version might be:

• 更衣室はこちらです。

Here, こちら is a more polite way to say this way / here.

Usually, no. Normal Japanese writing does not use spaces between words.

So it would normally be written:

• 更衣室はここです。

Spaces are often added only in beginner materials to make the sentence easier to read.

In very casual conversation, particles are sometimes dropped, but in a basic textbook sentence like this, you should keep は.

Standard form:

• 更衣室はここです。

Very casual speech might sometimes sound like:

• 更衣室、ここ。
• 更衣室、ここです。

But these are more conversational and depend on context. For learners, 更衣室はここです is the safest and clearest form.

It mainly means a changing room, but in real life it can overlap with locker room depending on the place.

For example:

• at a store: fitting/changing room
• at a gym or pool: locker room / changing room

The exact English translation depends on the situation, even though the Japanese word stays the same.