None of us was/were able to communicate with the alien. Now, I was taught to find the head subject and then form the verb according to the number of this head subject, but here I am not sure whether none of modifies us (> were) or of us modifies none (> was).
Oddly, Google has this to say:
none of us was able (1.460 occurences, 60%) none of us were able (970 occurences, 40%)
but also,
none of us is able (9.420 occurrences, 91%) none of us are able (897 occurrences, 9%)
How strange! The preference seems to change according to the tense of the verb. What do you make of it? Can the difference in frecuency be explained by the use of subjunctive "were"? And, which of the four varieties would you allow in an essay?