引号主要用于直接引语.引语内句首字母需大写,句尾要用句尾标点符号,并要点在引号以内. e.g Mother said,"I've heard Anny sing at the party." 

引号内如果再有引语,可分别用双引号和单引号予以区别,但是句尾只能用一个句子标点符号. e.g Helen inquired,“Did you hear him ask,‘who are you?'”