An der Haltestelle steigen wir in die U-Bahn.

German often puts the time/place information first for emphasis or style.

So:

• An der Haltestelle steigen wir in die U-Bahn.

has the same basic meaning as:

• Wir steigen an der Haltestelle in die U-Bahn ein.

When a phrase like An der Haltestelle comes first, the conjugated verb must still stay in second position. That is why you get:

• An der Haltestelle = position 1
• steigen = position 2
• wir comes after the verb

This is a very common German word-order pattern.

Because German uses the verb-second rule in main clauses.

The first element in the sentence is An der Haltestelle, so the finite verb must come next:

• An der Haltestelle steigen wir ...

If the subject comes first, then you would say:

• Wir steigen an der Haltestelle ...

Both are correct. The difference is mainly in focus and word order, not core meaning.

It is dative.

The preposition an can take different cases depending on meaning:

• dative for location: at / by
• accusative for movement toward something

Here, An der Haltestelle means at the stop, so it describes a location, not movement toward the stop. That is why it is dative:

• die Haltestelle → dative singular: der Haltestelle

So:

• an der Haltestelle = at the stop

In German, an is often used for being at a point, edge, stop, station, wall, river, etc.

So:

• an der Haltestelle = at the stop
• am Bahnhof = at the train station
• an der Ecke = at the corner

English speakers often expect in, but German chooses prepositions differently. You usually learn them as part of the phrase:

• an der Haltestelle
• am Bahnhof
• an der Bushaltestelle

Because this phrase expresses movement into the subway, not being located inside it.

German in can take:

• accusative for movement/direction
• dative for location

Compare:

• Wir steigen in die U-Bahn. = We get into the subway.
• Wir sind in der U-Bahn. = We are in the subway.

So here:

• die U-Bahn is accusative
• because the action goes into it

Good question. The full verb is usually einsteigen = to get in / board.

In many sentences, that separable prefix appears at the end:

• Wir steigen in die U-Bahn ein.

But in this sentence, you see:

• An der Haltestelle steigen wir in die U-Bahn.

This is also natural because in die U-Bahn steigen itself already clearly expresses the idea of getting into it. In real German, though, many learners will most often meet:

• in die U-Bahn einsteigen
• in den Bus einsteigen
• ins Auto einsteigen

So yes, einsteigen is the usual dictionary form, but in etwas steigen can also work depending on style and context.

On its own, steigen often means to climb, to rise, or to go up. But with transport, German commonly uses it in expressions involving getting in or getting on.

Very common transport verbs are:

• einsteigen = get in / board
• aussteigen = get out / get off
• umsteigen = change trains/buses/etc.

So in this sentence, steigen ... in die U-Bahn means to board the subway or to get on the subway.

Because U-Bahn is a feminine noun in German:

• die U-Bahn

It is short for Untergrundbahn, and it means subway / metro / underground.

Case forms here:

• nominative: die U-Bahn
• accusative: die U-Bahn
• dative: der U-Bahn

In this sentence, it is accusative after directional in, but for a feminine noun, the accusative form still looks like die.

Haltestelle means a stop, usually for public transport such as a bus or tram.

It is feminine:

• die Haltestelle

Examples:

• an der Haltestelle = at the stop
• die nächste Haltestelle = the next stop

It does not usually mean a large train station. For that, German more often uses:

• der Bahnhof = train station

Yes, absolutely. That is a very standard version.

Compare:

• Wir steigen an der Haltestelle in die U-Bahn ein.
• An der Haltestelle steigen wir in die U-Bahn ein.

Both are correct. The difference is just word order and what comes first for emphasis.

For learners, the version with ein at the end is especially useful because it clearly shows the separable verb:

• einsteigen

These mean different things:

• Wir steigen in die U-Bahn. = We get on / board the subway.
• Wir fahren mit der U-Bahn. = We go/travel by subway.

So steigen ... in die U-Bahn focuses on the moment of entering/boarding, while fahren mit der U-Bahn focuses on the mode of transport.

Because they describe two different relationships:

• an der Haltestelle = where the boarding happens
• in die U-Bahn = where you move into

So the sentence combines:

1. a location phrase
2. a direction phrase

That is completely normal in German.

You can think of it like:

• At the stop we get into the subway.