Please shed some light on "none" issue because I give up (below is why). Being non-native speaker is difficult enough and the 'issues' like this one make me only miserable.
1) Manhattan GMAT
Sentence Corrections says (p. 30) that "for SANAM (Some, Any, None, All, Most) pronouns you should look at the object of the 'of' construction to determine the number of the subject". Examples are:
a) Some of the money WAS stolen from my wallet. (money is singular)
b) Some of the documents WERE stolen from the bank. (documents is plural).
2) So then I move to Kaplan GMAT 800
and in the Sentence Correction Challenge the first example (p.135) is as follows:
As of this morning, none of my friends have been able to solve
the puzzle contained in last week's newspaper.
a) none of my friends have been able to solve
b) none of my friends was able to solve
c) not one of my friends has yet been able to solve
d) none of my friends has been able to solve
e) nobody among my friends have solved
Explanation: 'None' is singular and needs singular verb.
So if I understand it correctly and follow Manhattan GMAT
the correct answer would be A (have), but Kaplan
goes with D (has). ???????