Writing prompt: Dear Mr. Brown

Student essay:
I am glad to hear that you get on well with your maths teacher, Mr Green. Now I'd like to tell you about my favourite teacher.
My favourite is Mrs Guo who teaches me physics. She looks a little fat and often wears a comfortable black dress. It is said that fat people usually kind and humorous.That's true. Her lessons is always academic, but funny. She helps us solves problems enthusiastic. And that's way I like her so much.
Once,after a terrible test. I felt said and didn't want to continue studying. At this moment, Mrs Guo came here and taught me how to work out those questions simply with humorous language. She not only didn't shout to me critically, but also encouraged me friendly. I felt very warm and I liked her more than before.
I'm looking forward to hearing from you soon.
Yours Zky

Corrected essay:
I am glad to hear that you get on well with your maths teacher, Mr Green. Now I'd like to tell you about my favourite teacher.
My favourite is Mrs Guo who teaches me physics. She looks a little fat and often wears a comfortable black dress. It is said that fat people are usually kind and humorous. That's true. Her lessons are always academic, but funny. She helps us solve problems enthusiastically. And that's why I like her so much.
Once, after a terrible test, I felt sad and didn't want to continue studying. At this moment, Mrs Guo came here and taught me how to work out those questions simply with humorous language. She not only didn't shout to me critically, but also encouraged me friendly. I felt very warm and I liked her more than before.
I'm looking forward to hearing from you soon.
Yours, Zky

Error analysis:
error_sentence: It is said that fat people usually kind and humorous.
correct_sentence: It is said that fat people are usually kind and humorous.
correction: are
error_type: Sentence Structure Error
error_severity: 3
error_description: Sentence Structure Error: According to English grammar rules, the original sentence 〈fat people usually kind and humorous〉 lacks a linking verb and cannot form a complete subject-linking verb-complement structure. The subject 〈fat people〉 is plural, requiring the addition of the linking verb 『are』. Therefore, 〈fat people usually kind and humorous〉 is changed to 『fat people are usually kind and humorous』 to make the sentence structure complete and grammatically correct.

error_sentence: Her lessons is always academic, but funny.
correct_sentence: Her lessons are always academic, but funny.
error: is
correction: are
error_type: Subject-Verb Agreement Error
error_severity: 3
error_description: Subject-Verb Agreement Error: According to English grammar rules, the subject 〈lessons〉 is plural, so the verb needs to be the plural linking verb 『are』 to maintain subject-verb agreement. The singular 〈is〉 in the original sentence is incorrect; therefore, 〈is〉 is changed to 『are』.

error_sentence: She helps us solves problems enthusiastic.
correct_sentence: She helps us solve problems enthusiastically.
error: solves problems enthusiastic
correction: solve problems enthusiastically
error_type: Nonfinite Verb Form Error
error_severity: 3
error_description: ① Nonfinite Verb Form Error: In English, the structure 〈help sb do sth〉 requires the verb to be in its base form. In the original sentence, 〈solves〉 does not conform to this structure and should be changed to 『solve』; ② Adverb Error: According to English grammar rules, an adverb is needed to modify the verb phrase 〈solve problems〉. 〈enthusiastic〉 is an adjective and is incorrect; it should be changed to the adverb 『enthusiastically』.

error_sentence: And that's way I like her so much.

correct_sentence: And that's why I like her so much.

error: way
correction: why
error_type: Noun Error
error_severity: 3
error_description: Noun Error: According to the sentence's meaning, the intention is to express 'that is the reason why I like her so much'. The noun 〈way〉 (manner) is used incorrectly. The correct word should be 'why' to indicate a logical reason; therefore, 〈way〉 is changed to 『why』 to ensure correct meaning.

error_sentence: Once,after a terrible test.
correct_sentence: Once, after a terrible test, I felt sad and didn't want to continue studying.
error: .
correction: ,
error_type: Punctuation Error
error_severity: 2
error_description: Punctuation Error: According to English writing conventions, a comma is needed to connect the time adverbial 〈Once, after a terrible test〉 with the main clause. The period 〈.〉 in the original sentence inappropriately separates the sentence, leading to an incomplete structure. 〈.〉 should be changed to 『,』 to ensure a smooth connection.

error_sentence: I felt said and didn't want to continue studying.
correct_sentence: Once, after a terrible test, I felt sad and didn't want to continue studying.
error: said
correction: sad
error_type: Spelling Error
error_severity: 2
error_description: Spelling Error: According to the sentence's meaning, the intention is to express 'sad'. Therefore, 〈said〉 is a misspelling of 『sad』 and needs to be changed to 『sad』 to make the sentence coherent.

error_sentence: Yours Zky
correct_sentence: Yours, Zky
correction: ,
error_type: Punctuation Error
error_severity: 2
error_description: Punctuation Error: According to English writing conventions, a comma should be added after 〈Yours〉 at the end of an English letter to meet formatting requirements. The original phrase 〈Yours Zky〉 lacks a comma and should be changed to 『Yours, Zky』.