Learn Swedish: Vad mäktigt berget ser ut! - How majestic the mountain looks!

In Swedish, exclamations use Vad instead of Hur before an adjective to express surprise or strong feeling. If you used Hur, it would sound like you are asking a direct question about exactly how majestic the mountain is, rather than making an exclamation.

Why is there a -t at the end of mäktigt?

Even though this is an exclamation with a unique sentence structure, the adjective still has to agree with the noun it describes. Since berg is an ett word, the adjective takes the neuter -t ending to match berget.

Why is the subject berget placed before the verb ser?

Exclamatory sentences starting with Vad use straight word order, meaning the subject (berget) comes before the verb (ser). This is a great way to remember that exclamations don't use the reversed verb-subject order that normal questions do.

What role does ut play in this sentence?

It is the second half of the particle verb att se ut, which means 'to look' or 'to appear' (referring to physical appearance). Without ut, the verb ser would just mean 'sees' or 'is looking'.