How and When to Use the Word "Whom?"

Every semester there is at least one student that asks me this question.  It's a bit tricky and, until you know when to use "who" versus "whom," my best recommendation is simply never to use "whom" at all--always use "who." I say this because most of the time a faux pas in this instance will pass unnoticed by most Anglophones.

One simple way of thinking of this concept is that normally when the word "who" is preceded by a preposition, it becomes "whom:" 

• The person with whom I was speaking hung up the phone.
• The woman to whom you must speak is blind.
• For whom should I sign my autograph?

For those people that would like to have a more detailed explanation on how and when to use the word "whom," take a look at the following resource(s):

Website	Page Name	Comments
The Oatmeal	How and Why to Use Whom is a Sentence	I love this explanation because it is visual, clear and humorous.