提示用户输入一篇英语文章，然后对文中所有主语为第三人称单数形式的动词进行自动协议检查，将不一致的动词标记出来并给出正确的形式。
“Harry Potter and the Philosopher's Stone is a novel written by British author J.K. Rowling. The book tells the story of a young orphan boy named Harry who attends Hogwarts School of Witchcraft and Wizardry.”
The verbs "is" and "attends" are correctly in the third-person singular form agreeing with "Harry Potter and the Philosopher's Stone" and "Harry". No corrections needed.