schöner

In a sentence

• Das ist ein schöner Tag.

  This is a beautiful day.

  Here, "schöner" is used as an attributive adjective describing the noun "Tag" (day), and agrees in gender, case, and number with the noun.

• Berlin hat viele schöner Sehenswürdigkeiten.

  Berlin has many beautiful sights.

  Here, "schöner" is used in the genitive plural form as an attributive adjective describing the noun "Sehenswürdigkeiten" (sights).

• Ich finde diese Gegend schöner als die andere.

  I find this area more beautiful than the other one.

  Here, "schöner" is used as a comparative adjective in the predicate, comparing the current area "Gegend" to another one.