Teached

1850, Unknown Author, Jemmy Stubbins, or The Nailer Boy Chapter , I always like to be there to teach or to be teached.
1911, Ruth McEnery Stuart, Sonny, A Christmas Guest Chapter , His Sam failed to pass at the preliminar' examination, an' wasn't allowed to try for a diplomy in public; an' Enoch an' his wife, why, they seem to hold it ag'in' me thet Sonny could step in at the last moment an' take what their boy could n't git th'oo the trials an' tribulations of a whole year o' bein' teached lessons at home an' wrestled in prayer over.
1936-1938, Works Projects Administration, Slave Narratives Vol. XIV. South Carolina, Part 2 Chapter , Ole Missus and Marse learn't me to never tell a lie, and she teached me dat's de way to git along well.

The standard past of teach is taught.