Where does “[[skulan]], [[sulan]], [[scolan]]” come from?
[[skulan]], [[sulan]], [[scolan]] (Old High German) comes from Proto-West Germanic skulan, from Proto-Germanic skulaną, from Proto-Indo-European sḱel-, from Proto-Indo-European ḱelh₁- — to warm up, to be hot; to warm up, be hot.
Ancestry of “[[skulan]], [[sulan]], [[scolan]]”, step by step