Learn Turkish: Bu masalsı şehirde insanlar nasıl bu kadar misafirperver oluyor? - How are people so hospitable in this fairy-tale-like city?

It attaches to the noun masal (fairy tale) to create an adjective meaning "fairy-tale-like." You will see this suffix as -sı, -si, -su, or -sü added to nouns to mean "resembling" or "-ish," such as in çocuksu (childish) or erkeksi (masculine).

Why does this sentence use oluyor instead of just ending at misafirperver?

While you could simply ask insanlar nasıl bu kadar misafirperver?, adding oluyor (literally "becomes" or "happens to be") emphasizes that the speaker is actively observing an ongoing phenomenon. It gives the feeling of asking "How does it happen that people are so hospitable?" rather than just stating a static fact.

Does bu kadar always mean "this much"? Here it translates to "so".

Yes, bu kadar literally means "this much" or "to this extent." However, when placed before an adjective like misafirperver, it acts as an intensifier that translates naturally to "so" or "this" in English. The speaker is pointing out the extreme degree of the hospitality they are experiencing.

The word misafirperver is quite long. How is it constructed?