Singular "they," the gender-neutral pronoun, has been named the Word of the Year by the American Dialect Society this month. For example, "If anyone has a better idea, they’re welcome to try it."
It has been a long time since I was in high school, but it’s not true that dinosaurs were still around during my teenage years. However, I was taught to say, "If anyone has a better idea, he is welcome to try it." Such locutions, I admit, are now almost as out of date as tyrannosaurus rex.
Constructions like, "Everyone has to do their best for the team to win," started popping up on my students’ papers in the seventies. I used gallons of red ink correcting these sentences. I told my students that while such sentences might be politically correct, they were grammatically incorrect, because “everyone” is singular, and “their” is plural. Like many of the causes I have defended in my lifetime, this was a losing battle.
By the eighties and nineties, I knew I was going to lose, and I admitted that to my students, but I continued to urge them not to commit sins of grammar in writing. Then I found myself once in a while saying things like, "Everyone is entitled to their own opinion." When such sentences popped out of my mouth, I would say “oops,” and hope the grammar police had not heard me.
Now the American Dialect Society says it’s all right to use “they” as a gender-neutral pronoun. The Washington Post has adopted it in their style guide. I guess it’s okay to say, "Everyone looked out for their own interests." It’s okay, but I don’t think it will sound right to me. Everyone will do whatever they want anyway.