-슴다

Etymology
Contraction of 습니다 (seumnida).

Suffix

 * 1)  Colloquial version of 습니다 (seumnida), a declarative suffix in the  speech level.
 * 2)  the declarative suffix in the  speech level.

Usage notes
In parts of Hamgyong and Yanbian, this '슴다' form essentially replaces '습니다' as the declarative suffix in the formal polite speech level. Also, among younger Yukjin speakers both in Yanbian and North Korea it seems to be replacing the traditional and  suffixes.