Writing prompt: The Person I Like Best at School

Student essay:
Nancy is my favourite at school. She is my English teacher. She is very fair and helpful so everyone like her so much. She is an excellent lady,king-hearted,charitable,pious. She often helps me improve my English level etc. Once I failed in exam. She did not criticize me,but to help me. This is a memorable thing.
She is the best teacher that I met.

Corrected essay:
Nancy is my favourite at school. She is my English teacher. She is very fair and helpful so everyone likes her so much. She is an excellent lady, kind-hearted, charitable and pious. She often helps me improve my English level. Once I failed in an exam. She did not criticize me but helped me. This is a memorable thing.
She is the best teacher that I have met.

Error analysis:
error_sentence: so everyone like her so much.
correct_sentence: She is very fair and helpful so everyone likes her so much.
error: like
correction: likes
error_type: Subject-Verb Agreement Error
error_severity: 3
error_description: Subject-Verb Agreement Error: According to English grammar rules, when the indefinite pronoun 〈everyone〉 is the subject, it is third-person singular, and the predicate verb needs to be in the singular form. Therefore, the base form verb 〈like〉 is changed to the third-person singular form 『likes』, forming the correct subject-verb agreement structure 『everyone likes』.

error_sentence: She is an excellent lady,king-hearted,charitable,pious.
correct_sentence: She is an excellent lady, kind-hearted, charitable and pious.
error: king
correction: kind
error_type: Spelling Error
error_severity: 1
error_description: Spelling Error: According to compound adjective formation rules, 〈king〉 (king) in 〈king-hearted〉 is a spelling error and should be changed to 『kind』 to form the correct expression 『kind-hearted』 (kind), where the hyphen is indispensable.

error_sentence: She is an excellent lady,king-hearted,charitable,pious.
correct_sentence: She is an excellent lady, kind-hearted, charitable and pious.
error: ,
correction: and
error_type: Conjunction Error
error_severity: 3
error_description: Conjunction Error: According to English parallel structure rules, when multiple adjectives are listed, a conjunction is needed before the last element. Therefore, the final comma is replaced with the coordinating conjunction 『and』, forming the standard expression 『kind-hearted, patient and helpful』.

error_sentence: She often helps me improve my English level etc.
correct_sentence: She often helps me improve my English level.
error: etc
error_type: Word Redundancy Error
error_severity: 3
error_description: Word Redundancy Error: According to formal writing norms, 〈etc〉 (et cetera) is mostly used in informal contexts to indicate an incomplete list, whereas the sentence 〈improve my English level〉 already fully expresses the meaning; deleting 〈etc〉 makes the expression more concise and standard.

error_sentence: Once I failed in exam.
correct_sentence: Once I failed in an exam.
correction: an
error_type: Determiner Error
error_severity: 2
error_description: Determiner Error: According to indefinite article usage rules, the countable noun 〈exam〉 requires the indefinite article 『an』 when referring to a single instance of an exam; therefore, adding 『an』 before 〈exam〉 makes the sentence grammatically complete.

error_sentence: She did not criticize me,but to help me.
correct_sentence: She did not criticize me but helped me.
error: ,but to help
correction: but helped
error_type: Verb Tense Error
error_severity: 4
error_description: ① Punctuation Error: According to English punctuation rules, a comma should not be used before the conjunction 〈but〉; deleting the redundant comma 〈,〉 makes the parallel clauses connected by 〈but〉 flow more naturally; ② Preposition Error: According to the principle of parallel structure, the parallel predicates 〈did not criticize〉 and 〈to help〉 need to maintain consistent verb forms; therefore, the infinitive 〈to help〉 is changed to the past tense 『helped』, forming the correct structure 『did not criticize but helped』; ③ Verb Tense Error: According to the principle of tense consistency, the verb 〈help〉 needs to be changed to the past tense 『helped』 to maintain consistency with the past tense of the preceding predicate verb 〈did not criticize〉.

error_sentence: She is the best teacher that I met.
correct_sentence: She is the best teacher that I have met.
correction: have
error_type: Verb Tense Error
error_severity: 3
error_description: Verb Tense Error: According to the usage rules of the present perfect tense, when the clause 〈that I met〉 expresses a past experience that still has an impact on the present, the present perfect tense should be used to emphasize continuity; therefore, the auxiliary verb 『have』 is added to change it to 『that I have met』.