Writing prompt: Assume you are organizing an international festival, and your friends will come to help. Please describe how you and your friends will organize the festival. Write a short essay of about 60 words on this topic.
Writing hints: Frank will help carry boxes; John will buy some drinks; Dale will send emails; Jack will play the violin.

Student essay:
There will be an international festival. Many people are busying in prepare it. Frank will help carry boxes, that's why he is strong. John will buy some drinks for all of people. Dale will send emails for competitions all around the world. What about Jack? He will play the violin. He i good at it.

Corrected essay:
There will be an international festival. Many people are busy preparing for it. Frank will help carry boxes. That's why he is strong. John will buy some drinks for all of them. Dale will send emails for competitions all around the world. What about Jack? He will play the violin. He is good at it.

Error analysis:
error_sentence: Many people are busying in prepare it.
correct_sentence: Many people are busy preparing for it.
error: busying in prepare
correction: busy preparing for
error_type: PoS Confusion Error
error_severity: 5
error_description: ① PoS Confusion Error: According to English grammar rules, “be busy doing” is a fixed phrase; in the original sentence, 〈busying〉 is a present participle, but here an adjective 『busy』 is needed to describe the subject's state, so 〈busying〉 is changed to 『busy』 to conform to grammar.; ② Nonfinite Verb Form Error: According to English grammar rules, “be busy doing” is a fixed phrase, requiring a gerund, so 〈in prepare〉 is changed to 『preparing』 to conform to grammar rules.; ③ Preposition Error: According to English grammar rules and context, the intention here is to express “preparing for something”; the original phrase 〈prepare it〉 lacks a preposition, so 〈prepare it〉 needs to be changed to 『preparing for it』 to conform to grammar rules and context.

error_sentence: Frank will help carry boxes, that's why he is strong.
correct_sentence: Frank will help carry boxes. That's why he is strong.
error: , that
correction: . That
error_type: Punctuation Error
error_severity: 2
error_description: Punctuation Error: According to English grammar rules, the original sentence parts 〈Frank will help carry boxes〉 and 〈that's why he is strong〉 are two independent clauses and should be separated by a 『.』; therefore, 〈,〉 needs to be replaced with 『.』 to make the sentence structure correct.

error_sentence: John will buy some drinks for all of people.
correct_sentence: John will buy some drinks for all of them.
error: people
correction: them
error_type: Pronoun Error
error_severity: 2
error_description: Pronoun Error: According to English expression conventions, the objective case of a plural noun should use the pronoun 『them』 to refer to the previously mentioned group to avoid repetition; therefore, 〈people〉 in the original sentence should be changed to 『them』 to conform to expression conventions.

error_sentence: He i good at it.
correct_sentence: He is good at it.
error: i
correction: is
error_type: Spelling Error
error_severity: 2
error_description: Spelling Error: According to the meaning of the sentence, the intention here is to express “is”; therefore, 〈i〉 is a misspelling of 『is』, and 〈i〉 needs to be changed to 『is』 to make the sentence meaning clear.