CREATE TABLE table_50521 ("Nominative" CLOB, "Ergative" CLOB, "Dative" CLOB, "Genitive" CLOB, "Instrumental" CLOB, "Adverbial" CLOB)

What instrumental has chven-s as the adverbial?
SELECT "Instrumental" FROM table_50521 WHERE "Adverbial" = 'chven-s'
SELECT "Instrumental" FROM "table_50521" WHERE "Adverbial" = 'chven-s'