The confusing "Who/Whom"

We are working to determine who it belongs to.

The above sentence is taken from a news item in a popular English daily.

The 'who' in the sentence does not appear to be grammatically correct and this will become more noticeable if the sentence is rewritten as "We are working to determine it belongs to who."

Obviously, 'who' (which is in the subjective case) cannot be used there. We need a 'whom' (which is in the objective case) to be the object of the preposition 'to' and hence, the sentence should have been "We are working to determine whom it belongs to."

The use of 'who/whom' has confused many writers including experienced ones.

For a simple guide on how to use 'who/whom', please see my earlier postings of February 5, 2011 and September 28, 2009.