Which Sentences Are Correct?

They all seem fine to me.

RuslanaThey all seem fine to me.

1. Any of the two books is useful.
2. Either of the two books is useful.
3. Either book is useful.

A native speaker told me all the sentences are incorrect. I agree with him that the first sentence is incorrect because 'any' refers to more than two items. However, he said I should say:

1. Either of the two books MAY BE useful.
2. Either book MAY BE useful.

In my opinion, the first sentence is not correct because 'either' refers to two items, so 'of the two books' is redundant.

What puzzles me is why 'IS' is wrong, but 'MAY BE' is correct.

"A native speaker told me all the sentences are incorrect."
A native speaker of other than the English language?
all sentences have good grammar

"What puzzles me is why 'IS' is wrong, but 'MAY BE' is correct."
And what puzzles 'me is how a native can say such nonsense.

May I hear from other native speakers.

Lol, Incho.

Yoong LiatI agree with him that the first sentence is incorrect because 'any' refers to more than two items.

It may refer to more than 2 items, but I don't think it's wrong to use "any" when only 2 items are implied.

Both IS and MAY BE sound fine to me.

"Any used as a pronoun is followed by a singular or plural verb depending on the intended meaning: Any of these suggestions is acceptable. [i.e., any one of the suggestions is acceptable]. Are any of the children [i.e. more than one of several children] coming? (Is any of the children coming? implies that one is expected, with uncertainty as to which)."


http://encarta.msn.com/encnet/features/dictionary/DictionaryResults.aspx?refid=1861586118

Any (one) of the two books is useful.

My New Oxford Dictionary says:
any is used to refer to one or some of a thing or number of things, no matter how much or how many
http://www.google.hu/search?hl=hu&q=%22any+of+the+two&meta =

Yoong Liat
1. Any of the two books is useful.
2. Either of the two books is useful.
3. Either book is useful.

Which of the sentences is/are correct? Or are all incorrect?

Here is my take: Any and either would sound more correct with a quantifier [one]. But the way they were posted, is still acceptable.

1. Any [one] of the two books is useful. = There are two books for you to choose from. Take you pick. they are both are useful.
2. Either [one] of the two books is useful. = A known quantity of books are specified. Both are useful.
3. Either book is useful. ok, but there could be more than 2 books, perhaps 3; meaning either book A, B or C could be useful..