Learn Hardcore German: Auf dem Heimweg ruft mich die Kundin an, um nach dem Kochbuch zu fragen. - On the way home the customer calls me to ask about the cookbook.

auf dem Heimweg is a prepositional phrase meaning “on the way home.” The preposition auf in the sense of “on” or “along” a route takes the dative case when it denotes location or time, so Heimweg (a noun) becomes dem Heimweg.

Why is the verb anrufen split into ruft and an in this sentence?

German has separable‐prefix verbs like anrufen (to call). In a main clause, the prefix (an) detaches and moves to the end of the clause, while the finite part (ruft) appears in the second position. Hence:
• ruft (finite verb) …
• an (separable prefix at the end)

Why is the order ruft mich die Kundin an instead of ruft die Kundin mich an?

German follows the V2 rule: the finite verb must be in second position. After the first element (Auf dem Heimweg), ruft comes second. What follows can be subject or object in either order. Placing mich (direct object) before die Kundin (subject) is allowed and often used for emphasis or flow. Both orders are grammatical, but here the speaker chooses to highlight the timing/location first, then the action, then “me,” and finally the caller.

Why is mich used instead of mir after anrufen?

anrufen is a transitive verb that takes an accusative object (“to call someone”). In German, the accusative form of “I” is mich, whereas mir is dative. So you say sie ruft mich an (“she calls me”).

Why is there um before the infinitive clause and zu before fragen?

German uses um … zu to express purpose (“in order to …”). The structure is:
• um introduces the subordinate clause,
• zu attaches to the infinitive verb at the end.
So um nach dem Kochbuch zu fragen means “in order to ask about the cookbook.”

Why is there a comma before um in the sentence?

In German, subordinate clauses—including purpose clauses introduced by um … zu—are separated from the main clause by a comma. Hence the comma before um.

Why is nach dem Kochbuch used here instead of something like für das Kochbuch?

When you “ask” about something in German, you use nach + dative: nach etwas fragen (“to ask about something”). für would imply “on behalf of” or “for the purpose of,” which doesn’t fit “asking about” a topic or object.

Why is Kochbuch capitalized even though it’s in the middle of the sentence?

In German orthography, all nouns are capitalized regardless of their position in the sentence. Kochbuch (“cookbook”) is a compound noun, so it must be capitalized.

What does Kundin mean, and why does it end with -in?

Kundin is the feminine form of Kunde (“customer” or “client”). The suffix -in marks a female person. Hence die Kundin = “the (female) customer.”