Writing prompt: Is It Necessary to Attend Training Classes?

Student essay:
Nowadays the students are mainly judged by there scores. In order to get better notes, more and more of them are having extra classes, sacrificing their own time on the weekend.
In my opinion, it's unnecessary for them to attend training classes.
When the students attend the extra classes, they won't concentrate themselves on the classes in their school. They'll consider it not serious to take a rest in the normal classes, because they can make it up on the weekends. They won't even do their homework seriously.
When the students attend training classes, they also don't have adequate time to have a rest or do some activities they really enjoy. Sometimes they even don't get enough sleep, and it'll directly lead to their inefficiency in the school.
Only when we make the best use of the classes in the school can we learn better. We can find our short points through doing our homeworks, and if we have any questions, our teachers are always glad to answer them. Attending training classes is just a waste of time and money.

Corrected essay:
Nowadays the students are mainly judged by their scores. In order to get better scores, more and more of them are having extra classes and sacrificing their own time on the weekend.
In my opinion, it's unnecessary for them to attend training classes.
When the students attend the extra classes, they won't concentrate on the classes in their school. They'll consider it not serious to take a rest in the normal classes, because they can make them up on the weekends. They won't even do their homework seriously.
When the students attend training classes, they also don't have adequate time to have a rest or do some activities they really enjoy. Sometimes they even don't get enough sleep, and it will directly lead to their inefficiency in school.
Only when we make the best use of the classes in school can we learn better. We can find our shortcomings through doing our homework, and if we have any questions, our teachers are always glad to answer them. Attending training classes is just a waste of time and money.

Error analysis:
error_sentence: Nowadays the students are mainly judged by there scores.
correct_sentence: Nowadays the students are mainly judged by their scores.
error: there
correction: their
error_type: Pronoun Error
error_severity: 3
error_description: Pronoun Error: According to English grammar rules, 〈there〉 as an adverb of place cannot express possession. It should be changed to the possessive pronoun 『their』 to refer to the scores of 〈students〉, ensuring the pronoun agrees with its antecedent in number and person.
error_sentence: In order to get better notes, more and more of them are having extra classes, sacrificing their own time on the weekend.

correct_sentence: In order to get better scores, more and more of them are having extra classes and sacrificing their own time on the weekend.

error: notes
correction: scores
error_type: Noun Error
error_severity: 2
error_description: Noun Error: According to semantic accuracy, 〈notes〉 usually refers to written records or musical symbols, while the context requires expressing academic evaluation. It should be replaced with 『scores』 or 『grades』 to accurately convey the meaning of 'exam results'.
error_sentence: In order to get better notes, more and more of them are having extra classes, sacrificing their own time on the weekend.

correct_sentence: In order to get better scores, more and more of them are having extra classes and sacrificing their own time on the weekend.

error: ,
correction: and
error_type: Conjunction Error
error_severity: 3
error_description: Conjunction Error: According to English rules for parallel structures, the parallel verb phrases 〈having extra classes, sacrificing time〉 connected by a comma need the comma to be changed to the conjunction 『and』 to avoid a comma splice and maintain sentence coherence.
error_sentence: When the students attend the extra classes, they won't concentrate themselves on the classes in their school.
correct_sentence: When the students attend the extra classes, they won't concentrate on the classes in their school.
error: themselves
error_type: Word Redundancy Error
error_severity: 3
error_description: Word Redundancy Error: According to verb usage, 〈concentrate〉 itself already implies 'to focus', making the reflexive pronoun 〈themselves〉 redundant. Simplifying to 『concentrate on』 is more in line with idiomatic English expression.
error_sentence: They'll consider it not serious to take a rest in the normal classes, because they can make it up on the weekends.
correct_sentence: They'll consider it not serious to take a rest in the normal classes, because they can make them up on the weekends.
error: it
correction: them
error_type: Pronoun Error
error_severity: 3
error_description: Pronoun Error: According to pronoun reference rules, 〈it〉 cannot refer to the plural noun 〈classes〉. It should be changed to the plural pronoun 『them』 to maintain number agreement.
error_sentence: Sometimes they even don't get enough sleep, and it'll directly lead to their inefficiency in the school.

correct_sentence: Sometimes they even don't get enough sleep, and it will directly lead to their inefficiency in school.

error: 'll
correction: will
error_type: Contraction Error
error_severity: 2
error_description: Contraction Error: According to formal writing conventions, 〈it'll〉 is a colloquial contraction. Formal contexts require the full form 『it will』 to maintain formality of language.
error_sentence: Sometimes they even don't get enough sleep, and it'll directly lead to their inefficiency in the school.

correct_sentence: Sometimes they even don't get enough sleep, and it will directly lead to their inefficiency in school.

error: the
error_type: Determiner Error
error_severity: 2
error_description: Determiner Error: According to fixed phrase rules, the abstract concept 〈in school〉 when expressing the abstract state of learning does not require an article. Delete 『the』 to conform to idiomatic expression.
error_sentence: Only when we make the best use of the classes in the school can we learn better.
correct_sentence: Only when we make the best use of the classes in school can we learn better.
error: the
error_type: Determiner Error
error_severity: 2
error_description: Determiner Error: According to fixed phrase rules, the abstract concept 〈in school〉 when expressing the abstract state of learning does not require an article. Delete 『the』 to conform to idiomatic expression.
error_sentence: We can find our short points through doing our homeworks, and if we have any questions, our teachers are always glad to answer them.
correct_sentence: We can find our shortcomings through doing our homework, and if we have any questions, our teachers are always glad to answer them.
error: short points
correction: shortcomings
error_type: Noun Error
error_severity: 2
error_description: Noun Error: According to English expression norms, 〈short points〉 is a Chinglish direct translation error and does not conform to idiomatic English expression. The correct noun to express defects should be 『shortcomings』, meaning flaws or deficiencies, which is more consistent with semantics and language habits.
error_sentence: We can find our short points through doing our homeworks, and if we have any questions, our teachers are always glad to answer them.
correct_sentence: We can find our shortcomings through doing our homework, and if we have any questions, our teachers are always glad to answer them.
error: homeworks
correction: homework
error_type: Noun Number Error
error_severity: 2
error_description: Noun Number Error: According to English grammar, 〈homework〉 is an uncountable noun and cannot take the plural suffix -s. Delete the plural suffix -s. The correct form is 『homework』 to conform to English grammar rules.