This is quite a complicated one and, indeed, most reference sources do state that “who” is used most of the time now, and that that can be seen as being correct. In other words, “whom” is dying out. And it’s a slightly nerve-wracking one to do, as people get in such a fuss about it.
But I think I’ve found a way to differentiate quickly between the two, so here goes …
Who is used when referring to the subject of the sentence (the person who is doing, we might say), and whom to the object (the person who is being done to).
So – “The person who is going to the ball”; “The person who is speaking to me”, but “The person whom I am taking to the ball”, “The person to whom I am speaking”
I hope I’ve got that the right way round!
For more troublesome pairs, choose the phrase in the category cloud to the right, or click here.
LibroEditing proofreading, editing, transcription, localisation 
Caz
July 14, 2015 at 2:24 am
Hello Liz, I have recently discovered your blog and very much appreciate how willing you are to share your knowledge.
Your ‘Troublesome Pairs’ blog is particularly helpful. I am wondering which word you would choose to use – toward or towards – in the following sentence. Sarah walked across the park toward/s the children. I am finding some writers using ‘toward’, but I don’t think this is proper English. I have always written ‘towards’ myself. If a writer is using ‘Ok’ in direct speech, should this be written out as the full word ‘Okay’?
Thanks Caz
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Liz Dexter
July 14, 2015 at 5:08 am
Hello Caz and thanks for your comment. Re towards / toward, it tends to be a UK / US English thing (with the UK people using towards) – although neither is wrong, one will feel more natural, probably. Re OK / Okay, you can use either, as long as you’re consistent and use the same form throughout. Hope that helps and that you continue to enjoy the blog!
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