Viele Menschen leben in der Stadt.

in

Breakdown of Viele Menschen leben in der Stadt.

• die Stadt: the city
• viel: many
• der Mensch: the person

Questions & Answers about Viele Menschen leben in der Stadt.

Why are Menschen and Stadt capitalized, but viele is not?

In German, all nouns are capitalized, no matter where they appear in the sentence.

• Menschen (people) is a noun → capitalized
• Stadt (city) is a noun → capitalized

Words like viele (many) are not nouns; here viele is a determiner/adjective describing how many people. Such words are normally not capitalized.

In the sentence you gave, Viele is capitalized only because it is the first word of the sentence. If it were in the middle of the sentence, it would be viele Menschen.

Why is it in der Stadt and not in die Stadt?

The preposition in can take either dative or accusative, depending on the meaning:

• Accusative = movement into somewhere
  
  • Example: Ich gehe in die Stadt. – I’m going into the city.
• Dative = location (no movement)
  
  • Example: Ich bin in der Stadt. – I’m in the city.

In your sentence, leben (to live) describes a location, not movement:

• Viele Menschen leben in der Stadt.
  → People live in the city (they are located there).

So in must take the dative, and the dative form of die Stadt is der Stadt → in der Stadt.

Why is it der Stadt if the article for Stadt is die?