Ang pasahero ay nakaupo sa upuan malapit sa bintana.

Ang marks the noun phrase that is the topic or focus of the sentence. Here, ang pasahero means the passenger as the main thing being talked about.

In this sentence, pasahero is not marked because it is the “doer” in an English grammar sense, but because it is the topic of the sentence in Filipino.

Ay is a linker used in the inverted sentence pattern:

Ang pasahero ay nakaupo sa upuan malapit sa bintana.

This is a very common and correct structure, especially in writing or more careful speech.

A more natural everyday order is often:

Nakaupo ang pasahero sa upuan malapit sa bintana.

Both mean the same thing. The version with ay sounds a bit more formal or structured.

Yes. It is completely correct, and many speakers would find it more natural in conversation.

So you have two common patterns:

• Ang pasahero ay nakaupo sa upuan malapit sa bintana.
• Nakaupo ang pasahero sa upuan malapit sa bintana.

The first highlights ang pasahero first. The second begins with the predicate nakaupo.

Nakaupo describes a state: sitting or seated.

It comes from the root upo, which is related to sitting. In this sentence, nakaupo does not mean the action of sitting down; it means the person is already in that seated position.

A useful comparison:

• umupo = sat down / to sit down
• nakaupo = is sitting / seated

So nakaupo ang pasahero means the passenger is seated.

Sa is a very common marker for location, direction, and some other relationships. In this sentence it appears in:

• sa upuan = on/in the seat
• sa bintana = near the window

So the first sa marks where the passenger is sitting, and the second sa is part of the phrase malapit sa meaning near.

It can cover either idea depending on context. Filipino often uses sa where English has to choose between on, in, at, or to.

So nakaupo sa upuan is naturally understood as sitting on the seat or sitting in the seat, depending on what sounds best in English.

Malapit means near or close.
Sa bintana means to the window / by the window / near the window, depending on context.

Together:

malapit sa bintana = near the window

This whole phrase describes upuan here:

sa upuan malapit sa bintana = on the seat near the window

So it is the seat that is near the window.

In this sentence, the most natural reading is that it describes upuan:

the seat near the window

That said, in real usage, it also leads to the same general picture: the passenger is sitting in a place near the window. If you want to be extra clear, context usually does the work.

Filipino does not use articles in the same way English does. There is no direct all-purpose equivalent of the or a/an.

Instead, markers like ang, ng, and sa help show the role of a noun in the sentence.

So ang pasahero is often translated as the passenger, but ang does not equal English the word-for-word.

Upuan means seat or chair, depending on context.

It comes from the root upo (sit) plus a suffix that often forms a noun for a place or object associated with the action. So upuan is basically something to sit on.

In this sentence, seat is the best translation.

It is neutral to slightly formal because of the ay structure.

• Ang pasahero ay nakaupo sa upuan malapit sa bintana. = correct, neutral/written/slightly formal
• Nakaupo ang pasahero sa upuan malapit sa bintana. = correct, very natural in speech

So if you are learning conversational Filipino, it is good to recognize both.

Yes. That is a very good close translation.

Depending on context, natural English might also be:

• The passenger is sitting in the seat near the window.
• The passenger is seated near the window.

The Filipino sentence clearly includes upuan, so seat is part of the meaning.

Bintana means window. In the phrase malapit sa bintana, it functions as the reference point for location:

near the window

So the sentence places the seat—and therefore the passenger—close to the window.