Embedded clauses are contained within the main clause, so are part of the main clause. Technically, then, the whole of, say, I persuaded kin to cook a nice meal is the main clause, but with a subordinate clause embedded within it; the same goes for all the other examples in (20) and (21) However, I will follow the Practice of treating the main clause as the part of the sentence that doesn’t include any subordinate clause.
Sone facts about main and subordinate clause.