“Whoever” and “Whomever”

In one of the most recent episodes of the popular British series, “Foyle’s War”, Foyle asks, “May I speak to whomever is in charge here?”

“Whomever” should be “whoever” in this sentence.  The reason for this is that “whoever is in charge here” is a subordinate clause, and as such it has a subject and a verb.  The subject is “whoever” and the verb is “is”.

As with “who” and “whom”, “whoever” is subject and “whomever” is object.  However, in the sentence above, the whole clause (“whoever is in charge here”) is the object.