orthography

例句：

1. 1.The teacher corrected the student's spelling mistakes during the lesson.
   老师在课上纠正了学生的拼写错误。
2. 2.The book's author has a deep knowledge of the subject's orthography.
   这本书的作者对主题的正字法有深入的了解。
3. 3.The orthography of the alphabet is based on the Greek letters.
   字母表的正字法是基于希腊字母的。