None is or are

Here's a simple rule of thumbs:

When you use 'none' with a plural noun, it takes a plural form. A plural noun suggests several discrete, countable units (e.g., cars, people, students.) 

• None of the cars in the car park are red.
• None of us are perfect.
• The teacher turned to the students and said "none of you (i.e., the students) have done the homework right."

When you use none with a singular noun, it takes a singular form. 
A singular noun is either not countable (e.g., water, art) or suggests a whole unit rather than many discrete units (e.g., money, food.) 

• None of the water is polluted.
• None of my art was selected for the exhibition.
• None of their money was spent on junk food.

Agree vs Sympathize vs Empathize

I recently said that I agree with someone although it is hard to sympathize with him. This lead to a conversation about the difference between the following phrases:

• I agree with you: This is usually just an acknowledgement.
• I sympathize with you: This goes beyond just an acknowledgement to an emotional response to what the other person is going through. You might feel pity or sorry for the person. 
• I empathize with you: This is even deeper than sympathizing. You don't just feel sorry. You understand how the other person feels because either you or someone close to you have been in a similar situation, or you are naturally a very empathetic person. Sympathizing does not necessarily mean that you can relate to someone in such an intimate level.