Pauses，gestures，body language，volume—these and many other tools available to us in speaking are not available to us in writing．Instead，as we write，punctuation marks allow us to tell our readers when to pause，which words go where，and so on．The purpose of most punctu-ation is to make the reading of sentences easier．Most punctuation is placed according to rules that can be applied mechanically．

说话时我们可以通过停顿、手势、体态语言及音量高低等手段进行调节，写作时我们则必须借助标点符号。使用标点符号的目的是告诉读者在哪里停顿，减少其阅读过程中的障碍。标点符号必须随自身的规律而运行。