The principal advantage you get when speaking your ideas or whatever you are thinking instead of writing them, is that when you use spoken words or language to communicate, often both individuals or parties speaking can do so at the same time.
Also, expressing your ideals verbally, makes communication more directly and instantaneous. Furthermore; in case there is a misunderstanding or any wrong interpretation, it can be taking care of or corrected almost immediately.
Although, there are no obvious reasons for writing to be more difficult than speaking, the lack of non-verbal expressions, cues and interactions when you use written communication, could make it more difficult to accurately convey your ideas when compared to speaking them.
