embedding on its own refers to all types of clauses occurring as subordinate parts of a superordinate clause. there are three types of sub-clauses: complement, relative, and adverbial. subordinators or relative pronouns indicate which sub clause is being used. center embedding (abbreviated "c" or "c") contains words of the superordinate clause on the left and the right of the sub-clauses. multiple center embedding of the same type of clause is called self-embedding.