Troublesome English word pairs -- who or whom?

What confusion?  When do you use who and when do you use whom?  And what's the difference?
Many people will tell you whom is incorrect and they use "who" all of the time.
Let me tell you folks, whom is still a very good and correct English word that has been misused and maligned by students, teachers and the general public.
The difference is real simple.
Who is used as a subject pronoun.
E.g. Who put the empty milk jug in the refrigerator?
E.g. Who wrote the Gettysburg Address.
Whom is used as an object pronoun.
E.g.  With whom are you going to the party? -- object of the preposition with
E.g.  You gave my new sweater to whom? -- object of the preposition to.
E.g.  Whom did you see at the party? -- used as a direct object. The sentence's structure becomes: you did see Whom (at the party)?
Whom is still around.  It is still correct as an object pronoun.  It is still the rule.  Abuse it if you will, ignore it if you must, but it's still right to use it. Whom will not go away any time soon.