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Hi teachers,

Which is correct, please: None of your friends is online or None of your friends are online?

I think the sentence with is is correct, since 'none' takes a verb form which goes with a singular subject. Am I right about this, please? 

Thank you all! 
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Technically (traditionally) is is correct. Current usage, however, is making are much more common (and comfortable for some people). Let your audience be your guide.
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LaboriousI think the sentence with is is correct, since 'none' takes a verb form which goes with a singular subject. Am I right about this, please?
In the strict grammatical subject/verb agreement, that is right. However, native speakers would use the rule of proximity agreement, and select the verb that agrees with the plural "friends."

Here is some information on notional and proximity agreement:
http://grammar.about.com/od/pq/g/proximityagreement.htm