Learn Hardcore German: Dieser Freund wohnt in einer großen Stadt.

In German, dieser emphasizes “this specific” friend as opposed to just “the friend.” It’s often used when pointing out or specifying one particular person you’ve already mentioned or are about to mention.

Why is it in einer großen Stadt and not in ein großer Stadt?

In German, after the preposition in (which indicates a location here), we need the dative case. In einer großen Stadt is dative feminine singular because Stadt is feminine. The indefinite article eine in the dative case changes to einer, and the adjective groß ends with -en to match the dative feminine form.

What’s the difference between wohnen and leben?

Both can mean “to live,” but wohnen typically refers to residing in a specific place, focusing on your home or dwelling. Leben is more general and can mean living in a broader sense, including one's lifestyle or the fact of being alive. In this sentence, wohnen indicates that the friend’s home is in a large city.

Why is the adjective written as großen rather than große?

In the dative case (feminine singular), the adjective ending after einer is -en, so we say in einer großen Stadt. If it were the nominative case, for instance eine große Stadt, you would see -e at the end of the adjective.

How would this sentence change if the city were plural, such as “several large cities”?

For multiple cities, you’d need the plural form in German. An example could be in mehreren großen Städten (“in several large cities”). Notice that mehreren (dative plural for “several”) and großen (dative plural adjective ending) match each other.