The pronoun "none"

park sang joonI'd like to know whether the pronoun "none" is a singular noun or a plural noun.

It's singular because it means 'not one'. Thus, 'none of them' ~ 'not one of the them'.

CJ

Thank you, Mr.Jim, for your valuable answer.
Then should I always use "is/was", not "are/were"?

park sang joonThen should I always use "is/was", not "are/were"?

Yes. That's the rule for formal usage, and it should be followed for formal writing.

In less formal situations, however, like ordinary, everyday conversations, it is extremely common to make the agreement with any noun or pronoun in the of-phrase that comes after 'none', thus:

Here is a good explanation:

Although uncountable nouns require none to be conjugated with a singular verb, e.g., None of this meat tastes right, the pronoun can be either singular or plural in most other cases, e.g., Fifty people applied for the position, but none were accepted., and None was qualified.

Thank you, Mr.Jim, for your continuing to answer.

Thank you, ozzourti, for your very helpful and informative answer.

This is what Random House Unabridged Dictionary says:

—Usage.Since NONE has the meanings “not one” and “not any,” some insist that it always be treated as a singular and be followed by a singular verb: The rescue party searched for survivors, but none was found. However, NONE has been used with both singular and plural verbs since the 9th century. When

Thank you, Cool Breeze, for your very informative answer.