sumimasen, kono seki ha aite imasu ka.

Here, すみません is being used to politely get someone’s attention, like Excuse me in English.

It can also mean I’m sorry, but in this sentence it is not really an apology. It is just a polite way to begin speaking to a stranger, such as on a train, in a café, or in a waiting room.

The particle は is written with the hiragana は, but when it is used as the topic particle, it is pronounced wa.

So:

• 席は = seki wa
• not seki ha

This is one of the first spelling-pronunciation mismatches learners encounter in Japanese.

は marks the topic of the sentence.

In この席は空いていますか, the topic is この席 — this seat.

So the sentence is structured like:

• As for this seat, is it vacant?

In natural English, we would usually just say:

• Is this seat free?

Japanese often introduces the thing being talked about first, then comments on it.

この means this, and it must be followed by a noun.

So:

• この席 = this seat

You cannot use この by itself. It always needs a noun after it.

Compare:

• この席 = this seat
• これ = this one

So if you want to say this seat, この席 is correct.

席 means seat, but it can also mean place or spot depending on context.

In this sentence, it most naturally means a physical seat, like:

• a train seat
• a bus seat
• a chair at a table

It is a very common word when talking about sitting places.

空いています comes from the verb 空く.

In this sentence, it means:

• is vacant
• is available
• is free

So この席は空いていますか asks whether the seat is unoccupied.

A useful nuance:

• 空いている often describes a resulting state, not just an action in progress.
• So it is not really is becoming empty
• It is more like is empty / is open / is available

Also, for a seat like this, the reading is usually あいています.

空きます is the basic polite present/future form of the verb 空く. It can mean something like will become empty or opens up depending on context.

But 空いています describes the current state:

• 空いています = is empty / is available right now

That is why it is used here. The speaker wants to know the present condition of the seat.

か marks the sentence as a question in polite Japanese.

So:

• 空いています = is vacant
• 空いていますか = is it vacant?

In polite speech, か is very common at the end of yes/no questions.

Yes, it is polite and natural.

It is polite because:

• it begins with すみません
• it uses the -ます form: います
• it ends with か, which makes it a polite question

This is a very normal way to ask a stranger if a seat is free.

A more casual version might be:

• この席、空いてる？

But the original sentence is safer and more appropriate in public situations.

Japanese often leaves out subjects and objects when they are obvious from context.

In English, you might think of it as:

• Excuse me, is this seat free?

There is no need to say:

• Excuse me, is this seat free for me to sit in?
• Are you using this seat?

Japanese prefers the shorter, more context-based version. The listener understands what is meant.

No. Standard Japanese is usually written without spaces.

So normally it would be written as:

• すみません、この席は空いていますか。

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

Yes, in natural English that can be a very good translation.

Even though the Japanese literally asks whether the seat is empty / available, the natural English equivalent in many situations is:

• Is this seat free?
• Is anyone sitting here?

So the exact English wording can change depending on what sounds most natural, even when the Japanese sentence stays the same.