Why is free writing also called 'automatic writing'?
Free writing means writing by just brainstorming and without editing. So it is also called as automatic writing.
How do you differentiate writing from speaking?
Writing is a skill to present yourself through letters whereas speaking is a skill to deliver your feelings through words coming out of your mouth. People may not understand what you write but will definitely understand what you say. Even though you have writing skills if you can't deliver a speech then your skills does not really count. Writing is theory whereas speaking is practical.