In her famous Blue Book of Grammar and Punctuation and at the grammarbook.com site, Jane Straus gives the following examples and brief explanations of the use of whoever and whomever:
1.Give it to whoever/whomever asks for it first.
He asks for it first. Therefore, whoever is correct.
2.We will hire whoever/whomever you recommend.
You recommend him. Therefore, whomever is correct.
3.We will hire whoever/whomever is most qualified.
He is most qualified. Therefore, whoever is correct.
On reading this, I tried to come up with more complicated situations, and here is the one which puzzled me:
My dad said: Give the money to whoever/whomever who you are sure can't get by without it.
My speculation: My next door neighbors need the money badly and I'm sure they can't get by without it. So I give it to them. Therefore, whomever is correct.
My dad said: Give the money to whoever/whomever who you are sure can't get by without it.
My speculation:They need the money badly, and I'm sure that it's "they" who can't get by without it. So I give the money to those who can't get by without it. Therefore, whoever is correct.
But can it really be that the both sentences are correct? I doubt that. There must be a flaw in my speculations. Where is it?
Any help will be greatly appreciated.