Der Arzt arbeitet im Krankenhaus.

in

Breakdown of Der Arzt arbeitet im Krankenhaus.

• arbeiten: to work
• der Arzt: the doctor
• das Krankenhaus: the hospital

Questions & Answers about Der Arzt arbeitet im Krankenhaus.

Why is the article der used with Arzt instead of den or some other article?

In German the nominative case marks the subject of the sentence. Arzt is the subject here, so we use the masculine singular nominative definite article der.

• Den would be the masculine singular accusative article (used for direct objects), not appropriate for the subject.

Why is the phrase im Krankenhaus used instead of ins Krankenhaus or in das Krankenhaus?

• Im is a contraction of in
  • dem.
• When expressing location (being inside a place without movement), German uses in with the dative case, so dem Krankenhaus → im Krankenhaus.
• Ins (in + das) is the accusative form, used when indicating movement into a place. Here the doctor already works inside the hospital (no motion), so we choose the dative form im.

How do we know Krankenhaus takes dem (and becomes im) rather than der or den?

Each noun in German has a grammatical gender. Krankenhaus (hospital) is neuter, so its dative singular is dem Krankenhaus.
• Nominative: das Krankenhaus
• Accusative: das Krankenhaus
• Dative: dem Krankenhaus
→ in + dem → im.

Why is arbeitet used and not another form of the verb?

Arbeiten is a regular (weak) verb. In the present tense you remove -en and add the appropriate ending for each person:
• ich arbeite
• du arbeitest
• er/sie/es arbeitet
Since der Arzt is third person singular, the ending -et is added, giving arbeitet.

Can we use a different preposition, like bei, instead of in with arbeiten?

Yes. You can say Der Arzt arbeitet beim Krankenhaus (bei + dem → beim).

• bei emphasizes the institution or employer.
• in emphasizes being physically inside the building.
  Both are correct; the choice depends on what you want to highlight.

Why is Krankenhaus capitalized?

In German, all nouns are capitalized, without exception. Every noun—common, proper, abstract, or compound—starts with a capital letter.

Is Krankenhaus a compound word? How is it formed?

Yes. It’s formed by combining krank (sick) + Haus (house).
German often creates new nouns by directly compounding existing ones: • Krankenhaus = “sick-house” → “hospital.”