From Middle High German and Old High German stein, from Proto-West Germanic *stain, from Proto-Germanic *stainaz. Cognates include German Stein, Dutch steen, English stone, Swedish sten. The alternation between the stems Steen and Steng is due to the Luxembourgish velarisation of -n- that took place only in open syllables. (The plural used to have the ending -e, as it still does in German.) Similar alternations are found in some other nouns (e.g. Latäin, Schwäin, Wäin), but Steen is the only one that retains distinct stems for singular and plural.