Hoy había menos gente en el vagón de la que esperábamos, y hasta encontramos un asiento junto a la ventana.

Había is the imperfect, which is often used for background description or a situation that was simply the case at that moment.

Here, the speaker is describing what the carriage was like: there were fewer people in it than expected.

• Había menos gente... = there were fewer people / there was less of a crowd
• Hubo menos gente... would sound more like a completed event or a counted occurrence, which is less natural here

So había fits because it paints the scene.

This is a very common contrast in Spanish:

• imperfect = background, description, ongoing situation
• preterite = completed event, something that happened

In this sentence:

• había menos gente describes the situation in the carriage
• encontramos un asiento tells us the specific thing that happened next

So the sentence is structured like this:

• background: Hoy había menos gente...
• event: y hasta encontramos un asiento...

That contrast is very natural in Spanish storytelling.

Here, de la que esperábamos is part of a comparative structure meaning than we expected.

The whole idea is:

• menos gente de la que esperábamos = fewer people than we expected

Spanish often uses de lo que or an agreeing form like de la que after más or menos when what follows is a clause.

Why la?

Because it agrees with gente, which is grammatically feminine singular:

• la que → referring back to gente

So the structure is basically linking back to that noun:

• menos gente de la que esperábamos

A very similar alternative you may also hear is:

• menos gente de lo que esperábamos

Both are natural, but de la que ties more directly to gente.

Esperábamos is the imperfect, and here it means something like we were expecting.

The sentence is referring to an expectation that existed before or at the time they saw the carriage. That makes the imperfect natural.

• esperábamos = we were expecting / we expected
• esperamos = we waited / we hoped / we expect, depending on context, but not right here

So in this sentence, esperábamos is not about one finished act of expecting. It is the prior expectation in the speakers’ minds.

Grammatically, gente is singular, even though it refers to many people.

So Spanish treats it as a singular collective noun:

• mucha gente
• poca gente
• menos gente

And with verbs/adjectives, standard Spanish normally uses singular agreement:

• Había mucha gente
• La gente estaba cansada

Not:

• Habían mucha gente
• La gente estaban cansados

Also, gente usually does not take a plural in this meaning. Gentes exists, but it means something more like peoples or different groups of people, not simply people in a carriage.

No. Here hasta means even.

So:

• y hasta encontramos un asiento = and we even found a seat

It adds a sense of surprise, as if finding a seat was better than expected.

This is a very common use of hasta in Spanish:

• Hasta me llamó = He/She even called me
• Hasta los niños lo entendieron = Even the children understood it

So hasta does not mean until in this sentence.

Vagón usually means a carriage or car of a train or metro.

So el vagón here is not the whole train; it is one section of it.

In Spain, this is very normal vocabulary for:

• trains
• metro/subway
• sometimes other rail transport

So:

• en el vagón = in the carriage / in the train car

Junto a la ventana means next to the window or by the window.

Yes, al lado de la ventana is also correct and very natural.

The difference is small:

• junto a can sound a bit more compact or slightly more formal/written
• al lado de is very common in everyday speech

So all of these are natural:

• un asiento junto a la ventana
• un asiento al lado de la ventana

In transport contexts, you may also hear things built around ventanilla, especially when talking about a window seat.

Because menos is the normal word for less/fewer when talking about quantity.

So:

• menos gente = fewer people / less of a crowd

Menor is an adjective, and it usually means smaller, lesser, or younger/minor, depending on context. It is not the normal way to talk about quantity here.

Compare:

• menos gente = fewer people
• una cantidad menor de gente = a smaller number of people

That second version is possible, but more formal and less direct. In normal Spanish, menos gente is the natural choice.

Spanish usually needs an article with countable singular nouns in this kind of sentence.

So:

• encontramos un asiento = we found a seat

Without un, the sentence would sound incomplete or ungrammatical in normal Spanish.

The article is indefinite because the seat is not identified beforehand. It is just one seat they happened to find, not a specific previously known seat.