I teach Grammar in an English class in Malaysia and this is THE one main problem I do not seem to have the answer to:

When exactly do you use WHO and likewise, 'WHOM'?

I have read many many Grammar books but I do not see the light at the end of the tunnel...someone help!

many thanks.
Formally, use 'who' as the subject of a verb and 'whom' as the object of a verb or preposition.

'Who bought your house?'
'To whom did you sell your house?'
'That is the sucker who bought my house.'
'That is the sucker to whom I sold my house.'

Where we run into trouble is:

'That is the sucker who(m) I know to have bought my house.' Is it 'who' as the subject of 'to have bought' or 'whom' as the object of 'know'? Nobody knows. So 'whom' is considered more correct, because 'whom' is more formal.

In informal English, these are perfectly acceptable:

'Who did you sell your house to?'
'That is the sucker I sold my house to.'

That's a start. Here's some more thoughts at [url="http://www.getitwriteonline.com/archive/062802.htm"]GET IT WRITE[/url]

Thanks for the prompt reply. Really appreciate it.