Questions & Answers about Das Gymnasium in unserer Stadt ist sehr alt.
Why does Gymnasium mean "grammar school" instead of "gym"?
Gymnasium is a classic false friend! In German, it refers to an academic high school or grammar school that prepares students for university. If you want to say "gym" as in a place to work out, use das Fitnessstudio or die Turnhalle (sports hall).
Why is it in unserer Stadt and not in unsere Stadt?
The preposition in is a two-way preposition. Here, it describes a fixed location (answering "where?" or wo?), which requires the dative case. Because Stadt is feminine (die Stadt), the possessive unsere takes the feminine dative ending -er, becoming unserer.
Why doesn't the adjective alt have an ending here?
In German, adjectives only get endings when they appear directly in front of a noun (like ein altes Gymnasium). When an adjective comes after the noun and is linked by a verb like ist (to be), it is called a predicate adjective and stays in its base form without any endings.