I believe that you can do just about anything in a story as long as you execute it well.
I will unsparingly point out any and all errors of grammar, spelling or usage that I happen to see, regardless of how old/young you are, whether English is your first or tenth language, whether you are dyslexic or ADD or anything else.
I will not, however, mock you for making these errors. Everyone has to learn somehow.
All I ask of you is that you not take any criticisms I make personally. Writing is hard work. You may not want to revise or change something, or take my suggestions, but you shouldn't expect it to be perfect the first time - or any time, really.
I do not recommend any books on how to write. They have seldom helped me. The best way to learn to write is to read great authors, and read them and read them and read them until the book falls apart and you have to buy another copy, then read that until it falls apart. Learn how people really talk. Observe life. Carry a notebook or a laptop with you and write down things that inspire you.
Why do I write fanfic? I'm not sure, but I've been doing it all my life. I wrote Little House on the Prairie fanfic when I was seven or eight, for a school assignment. I would prefer to work on something I could perhaps publish and see money for, but I can't help writing fanfic. I only recently started putting my fanfic online because at least this way it'll not be a total waste of time.