Wooden Heart", created by Fred Wise, Ben Weisman, Kay Twomey and German bandleader Bert Kaempfert, was based on a German folk song by Friedrich Silcher, "Muss i denn", originating from the Rems Valley in Württemberg, southwest Germany. "Wooden Heart" features several lines from the original folk song, written in the German Swabian dialect, as spoken in Württemberg.
Marlene Dietrich recorded a version of the song sometime before 1958, pre-dating Presley, in the original German language, which appears as a B-side on a 1959 version of her single "Lili Marlene", released by Philips in association with Columbia Records.
The Elvis Presley version featured two parts in German, the first one is the first four lines of "Muss i' denn zum Städtele hinaus", whereas the second part appears towards the end and is based on a translation of the English version (therefore not appearing in the original German folk lyrics). This part being Sei mir gut, sei mir gut, sei mir wie du wirklich sollst, wie du wirklich sollst... ("Be good to me, be good to me, be to me how you really should, how you really should...").
https://en.m.wikipedia.org/wiki/Wooden_Heart