I believe that biological gender is unchangeable. It's what you were born as. You were born with either a penis or vagina, and in some very rare cases; both.

However, gender identity is something else entirely. You can be a man who wants to be a woman, so you would undergo the proper treatments and surgeries, until you resembled what you wanted on the outside. Only rarely do these people turn out EXACTLY how they wanted.

Those who have a penis, but want to be a woman, while dressing as a woman, is a transgender. They want to be treated like a woman and adopt the womanly roles even though they're a man.

Those who believe they are another gender in another body clearly have some sort of mental illness. However, not all mental illness is bad. It's something that can be fixed or sorted.

I would call a man a woman if he dressed like a woman, acted like a woman, and adopted the womanly roles. I'd even refer to him as 'she', and 'her'.

However, those people who just want to be treated like some special snowflake and have the pronouns 'xir' and 'xhe' is retarded. There are only two genders, with some people having both, but normally identify as a man or a woman.

There's just way too much focus on gender/race now a days, can't we just call people idiots because of what they say/do, not by what they look like?