Learn Hardcore German: Ich sitze auf der Bank im Park und lese ein Buch. - I sit on the bench in the park and read a book.

German prepositions like auf can govern either dative or accusative. When you indicate a static location (answering wo?), you use the dative. If it expressed movement toward something (answering wohin?), it would take the accusative. Sitting on a bench is location, hence dative: die Bank → der Bank.

Why is it der Bank and not die Bank or den Bank?

The noun Bank is feminine (die Bank). In the singular dative, the feminine article die changes to der. Therefore die Bank becomes der Bank in dative.

What does Bank mean in this sentence — bench or financial bank?

In German, Bank can mean both “bench” and “bank” (financial institution). Here, the context im Park (in the park) shows that it’s a bench.

Why is im Park used instead of in dem Park?

im is simply the contracted form of in dem. Both are correct; Germans usually shorten it to im in everyday language.

What’s the difference between ich sitze and ich setze mich?

sitzen is intransitive: “to sit,” describing your posture.
setzen can be transitive (“to set/seat something”) or reflexive (sich setzen, “to seat oneself”).
Since you’re already in a seated position, you use ich sitze rather than ich setze mich, which would stress the action of sitting down.

Why is the simple present tense used for “reading” instead of a continuous form?

German does not have a separate continuous aspect (like English “I am reading”). The simple present (ich lese) covers both habitual and ongoing actions, with context clarifying the meaning.

Why does the sentence use two verbs (sitze and lese) without repeating ich?

The verbs sitze and lese share the same subject (ich). German allows you to connect two predicates with und in one clause without repeating the subject pronoun: ich sitze ... und lese ....

Why is there no comma before und?

In German, you generally do not put a comma before coordinating conjunctions like und when they link verbs, phrases, or main clauses that share the same subject.

Why are the words Bank, Park, and Buch capitalized?

A fundamental rule of German orthography is that all nouns are capitalized, not just proper names.

Why is it ein Buch in the accusative case, and how do we know it’s accusative?

The verb lesen requires a direct object (what are you reading?), so the object (Buch) goes into the accusative case.
Buch is neuter, and the indefinite article in the neuter accusative is ein (unchanged), unlike the masculine accusative (einen).