An der Raststätte trinken wir Kaffee und essen ein Brötchen.

Raststätte is a motorway service area or rest stop. It usually means a place on or by a highway where people can stop, park, use the restroom, and often buy food or drinks.

It is a bit more specific than just a place to rest.

German prepositions do not match English prepositions one-for-one.

The preposition an can mean things like:

• at
• on
• by
• next to

In an der Raststätte, the natural English translation is at the rest stop.

So it is better not to translate an mechanically every time. Learn the whole phrase an der Raststätte as a location expression.

Because this sentence describes a location: where are we drinking coffee and eating a bread roll?

• where? → usually dative after a two-way preposition like an
• where to? → usually accusative

Here, the meaning is at the rest stop, not to the rest stop, so German uses the dative:

• an der Raststätte = at the rest stop

Raststätte is a feminine noun:

• nominative: die Raststätte

But after an in a location meaning, it takes dative, and the feminine definite article changes like this:

• nominative feminine: die
• dative feminine: der

So:

• die Raststätte
• an der Raststätte

Because German is a verb-second language.

In a normal statement, the finite verb must be in the second position. If you move a different part of the sentence to the front, the verb still stays second.

Here, An der Raststätte is placed first for emphasis or topic:

1. An der Raststätte
2. trinken
3. wir

So:

• Wir trinken Kaffee ... = neutral order
• An der Raststätte trinken wir Kaffee ... = the location is put first

This is very common in German.

Yes, that is also grammatical.

The difference is mainly focus:

• An der Raststätte trinken wir Kaffee und essen ein Brötchen.
  → emphasizes where this happens

• Wir trinken Kaffee und essen ein Brötchen an der Raststätte.
  → starts more neutrally with we

German word order is flexible, but the verb still has to stay in the right place.

Because Kaffee is being used as an uncountable substance / general food-drink item, similar to English drink coffee.

German often leaves out the article with food and drink in this kind of general sense:

• Wir trinken Kaffee.
• Sie essen Brot.

If you add an article, the meaning changes a bit:

• einen Kaffee trinken = drink a coffee / a cup of coffee
• den Kaffee trinken = drink the coffee (specific coffee already known)

So Kaffee without an article is very natural here.

Because Brötchen is neuter.

The ending -chen is a very useful clue: nouns ending in -chen are always neuter in German.

So:

• das Brötchen = the bread roll
• ein Brötchen = a bread roll

Also, in this sentence Brötchen is the direct object, so it is in the accusative. For neuter nouns, the indefinite article is still ein in both nominative and accusative.

That is why:

• ein Brötchen is correct
• not eine Brötchen
• not einen Brötchen

Because all nouns are capitalized in German.

So in this sentence:

• Raststätte = noun
• Kaffee = noun
• Brötchen = noun

They all begin with capital letters.

Also, An is capitalized too, but only because it is the first word of the sentence.

Because the same subject, wir, applies to both verbs:

• trinken
• essen

So German, like English, does not need to repeat the subject:

• An der Raststätte trinken wir Kaffee und essen ein Brötchen.

This is the same idea as English:

• We drink coffee and eat a bread roll.

You could repeat wir, but then it sounds more separate or more emphatic:

• ..., und wir essen ein Brötchen.

Because und is simply joining two coordinated parts of the sentence:

• trinken wir Kaffee
• essen ein Brötchen

In German, you normally do not use a comma before und in this kind of structure.

So:

• ... trinken wir Kaffee und essen ein Brötchen. ✅

No comma is needed here.