Breakdown of Tämä alue ei ole julkinen, vaan yksityinen.
tämä
this
olla
to be
ei
no / not (en, et, ei, emme, ette, eivät)
alue
the area
Questions & Answers about Tämä alue ei ole julkinen, vaan yksityinen.
Why do we use vaan here instead of mutta to say but?
Both words mean "but", but vaan is specifically used after a negative statement to mean "but rather" or "instead". Because the first half of the sentence is negative (ei ole julkinen), vaan is used to introduce the direct correction. If you used mutta, it would sound like you are just adding contrasting extra information rather than correcting the negated idea.
Can I include the pronoun and verb after the comma, like ..., vaan se on yksityinen?
You can, and it would be grammatically correct. However, because the subject (Tämä alue) and the verb (on) are exactly the same for both halves of the contrast, Finnish usually drops them in the second half. It is much more natural and concise to just contrast the two adjectives directly.
Is the comma before vaan strictly required?
Yes. In Finnish punctuation rules, you almost always need a comma before coordinating conjunctions that signal a contrast, such as mutta (but) and vaan (but rather).
Both adjectives here end in -nen. How would these words change if we were talking about plural areas?