Speech keys human interaction. It is the first line of communication.
Toddlers implement common grammar rules without formal training.
In school, children learn to put their thoughts on paper, but they do not practice their developing skills by exchanging notes with their friends and family. Even as adults, speech remains the mode of first choice on the basis of natural skill and efficiency. Many students dread writing for class and for many adults, having to write in a formal setting is no less intimidating, but help is available to people who listen. The aural art of writing is not naturally occurring, although some people are predisposed to it and others come to discover it. Many people have difficulty putting their feelings into words.