Is this correct?

AnonymousAnn is one of my best friends. Is this right?

Yes.

thanks, this was really helpful.

Use of would, could, should in present & past & future in which condition.

That is far too big a topic for us to answer. Have a look at some of the other threads to see what sort of questions we deal with. Then write a qustion about a specific problem you have.

No its not right, because Ann is a single person so you should be writing (Ann is one of my best friend).
Suppose if you have two friends than you can use friends

Anonymous No its not right, because Ann is a single person so you should be writing (Ann is one of my best friends).Suppose if you have two friends than you can use friends

Actually this response is incorrect. You do need the plural of friends; Ann is one person, but she is one of several.

I agree with Philip

I agree

"Ann is one of my best friends."
This sentence is absolutely correct.

Another similar confusion that people usually come across is,

A. One of my friends is coming tonight.
or
B. One of my friends are coming tonight.

The first sentence "A" is correct.
People usually get confused & say that "friends" is a plural noun, they should be using "are" instead of

"One" in sentence "A" is the key.
"Some of my friends is coming tonight." incorrect
"Some of my friends are coming tonight" correct