Comparo el asiento numerado con la zona de pie.

Because comparo is the first-person singular form of the verb comparar in the present tense.

• comparar = to compare
• comparo = I compare

This follows a regular -ar verb pattern:

• yo comparo = I compare
• tú comparas = you compare
• él/ella compara = he/she compares

Spanish often drops the subject pronoun, so comparo by itself already tells you the subject is I.

In Spanish, subject pronouns are often omitted because the verb ending already shows who is doing the action.

So:

• Yo comparo el asiento numerado...
• Comparo el asiento numerado...

Both mean the same thing: I compare the numbered seat...

Including yo is usually only for emphasis, contrast, or clarity.

Spanish uses definite articles more often than English does. Here, el means the.

So:

• el asiento numerado = the numbered seat
• la zona de pie = the standing area

Even when English might sound natural with or without the, Spanish often prefers the article.

Literally, it means numbered seat.

In real usage, it usually refers to a seat that has an assigned number, such as in:

• a theater
• a stadium
• a bus
• a train

So it often implies a reserved or assigned seat, not just any seat with a number printed on it.

In Spanish, most adjectives normally come after the noun.

So:

• asiento numerado = numbered seat
• zona grande = big area
• boleto barato = cheap ticket

Putting numerado after asiento is the normal word order.

Here, con means with.

• Comparo X con Y = I compare X with Y

This is a very common structure in Spanish.

You may also sometimes see comparar X y Y, which is more like to compare X and Y. Both are possible, but comparar ... con ... is very standard and explicit.

Literally, it means the zone of standing or the standing zone.

The phrase de pie means standing or on foot/upright.

So:

• zona de pie = standing area
• entradas de pie = standing tickets
• viajar de pie = to travel standing up

In this sentence, la zona de pie refers to the area where people stand instead of sitting.

De pie is a fixed expression meaning standing or standing up.

Examples:

• Estoy de pie. = I am standing.
• Viajamos de pie. = We travel standing up.
• La zona de pie = the standing area

It does not literally mean something like of foot in normal English translation, even though that is how the words break down.

Because every Spanish noun has a grammatical gender.

• asiento is masculine → el asiento
• zona is feminine → la zona

The adjective must agree when needed:

• el asiento numerado
• la zona (no adjective here, but if there were one, it would match feminine form)

For example:

• la zona numerada = the numbered area

Yes. Comparo is in the simple present.

In Spanish, the simple present can often translate as:

• I compare
• I am comparing

depending on context.

So this sentence could mean either:

• I compare the numbered seat with the standing area
• I am comparing the numbered seat with the standing area

If you want to stress the ongoing action, Spanish can also use:

• Estoy comparando el asiento numerado con la zona de pie.

But the original sentence is completely natural.

Yes, a few alternatives are possible, depending on nuance:

• Comparo el asiento numerado y la zona de pie.
  = I compare the numbered seat and the standing area.

• Estoy comparando el asiento numerado con la zona de pie.
  = I am comparing the numbered seat with the standing area.

• Comparo el asiento asignado con la zona de pie.
  = I compare the assigned seat with the standing area.

The original sentence is correct and natural, especially if you want a straightforward compare X with Y structure.