Writing prompt: Should Students Be Allowed to Use Cellphones at School?

Student essay:
Nowadays, a number of students use cellphones at the school. The problem is whether we should allow students to use mobile phones at school.
As the say goes, every coin has two sides. Some students believe that phones bring us some convenience. It is convenient to contact with families and friends. Besides, when we are boring, we can use it to watch movies, play games, take photos and so on. In a word, it is very useful.
However, others hold the view that it has no goods. They think we can be addicted to the phones. It is bad for our eyes. Furthermore, if we spend too much time on it, our grades will fall behind.
In my opinion, cellphones make our life convenient and colorful. We should use it at the school. But we mustn't use it at class. It is wonderful for us, if we use it right.

Corrected essay:
Nowadays, a number of students use cellphones at school. The problem is whether we should allow students to use mobile phones at school.
As the saying goes, every coin has two sides. Some students believe that phones bring us some convenience. It is convenient to contact families and friends. Besides, when we are bored, we can use them to watch movies, play games, take photos, and so on. In a word, they are very useful.
However, others hold the view that they have no benefits. They think we can be addicted to phones. It is bad for our eyes. Furthermore, if we spend too much time on them, our grades will fall behind.
In my opinion, cellphones make our life convenient and colorful. We should use them at school. But we mustn't use them in class. It is wonderful for us if we use them right.

Error analysis:
error_sentence: Nowadays, a number of students use cellphones at the school.
correct_sentence: Nowadays, a number of students use cellphones at school.
error: the
error_type: Determiner Error
error_severity: 2
error_description: Determiner Error: According to English grammar rules, the definite article 〈the〉 indicates specificity, but it is not needed when referring to a school in a general sense; therefore, the original phrase 〈at the school〉 is changed to 『at school』 to comply with grammatical rules.
error_sentence: As the say goes, every coin has two sides.
correct_sentence: As the saying goes, every coin has two sides.
error: say
correction: saying
error_type: Noun Error
error_severity: 2
error_description: Noun Error: According to English idiomatic expressions, the fixed proverb 『As the saying goes』 requires the gerund 『saying』 to mean “proverb”; therefore, 〈say〉 needs to be changed to 『saying』 to make the sentence more idiomatic in English.
error_sentence: It is convenient to contact with families and friends.
correct_sentence: It is convenient to contact families and friends.
error: with
error_type: Preposition Error
error_severity: 2
error_description: Preposition Error: According to English grammar rules, the verb 〈contact〉 is a transitive verb and does not require a preposition when followed by an object; therefore, the redundant 〈with〉 is deleted, changing it to 『contact families』 to comply with grammatical rules.
error_sentence: Besides, when we are boring, we can use it to watch movies, play games, take photos and so on.
correct_sentence: Besides, when we are bored, we can use them to watch movies, play games, take photos, and so on.
error: boring
correction: bored
error_type: Adjective Error
error_severity: 2
error_description: Adjective Error: According to the prompt, the meaning here is “bored”; in the original sentence, 〈boring〉 describes the nature of something, but the context requires describing a person's feeling, so 〈boring〉 needs to be changed to 『bored』 to fit the context.
error_sentence: Besides, when we are boring, we can use it to watch movies, play games, take photos and so on.
correct_sentence: Besides, when we are bored, we can use them to watch movies, play games, take photos, and so on.
error: it
correction: them
error_type: Pronoun Error
error_severity: 2
error_description: Pronoun Error: According to English grammar rules, the pronoun 『them』 should be used for plural nouns; in the original sentence, 『phones』 is a plural noun, so the subsequent pronoun should be in the plural form 『them』 to maintain number agreement, thus 〈it〉 needs to be changed to 『them』 to comply with English grammar.
error_sentence: Besides, when we are boring, we can use it to watch movies, play games, take photos and so on.
correct_sentence: Besides, when we are bored, we can use them to watch movies, play games, take photos, and so on.
correction: ,
error_type: Punctuation Error
error_severity: 2
error_description: Punctuation Error: According to English writing conventions, a comma 『,』 should be added before the last item in a list for clear separation; therefore, a comma 『,』 needs to be added after 〈take photos〉 to conform to the convention.
error_sentence: In a word, it is very useful.

correct_sentence: In a word, they are very useful.

error: it is
correction: they are
error_type: Pronoun Error
error_severity: 2
error_description: Pronoun Error: According to English grammar rules, the pronoun 『they』 should be used for plural nouns; in the original sentence, 『phones』 is a plural noun, so the subsequent pronoun should be in the plural form 『they』 to maintain number agreement, thus 〈it is〉 needs to be changed to 『they are』 to comply with English grammar.
error_sentence: However, others hold the view that it has no goods.
correct_sentence: However, others hold the view that they have no benefits.
error: it has no goods
correction: they have no benefits
error_type: Pronoun Error
error_severity: 4
error_description: ① Pronoun Error: According to English grammar rules, the pronoun 『they』 should be used for plural nouns; in the original sentence, 『phones』 is a plural noun, so the subsequent pronoun should be in the plural form 『they』 to maintain number agreement, thus 〈it has〉 needs to be changed to 『they have』 to comply with English grammar; ② Noun Error: According to the context, the meaning here is “benefits”; 〈goods〉 means “items,” which does not fit the context, so 〈goods〉 needs to be changed to 『benefits』 to fit the context.
error_sentence: They think we can be addicted to the phones.
correct_sentence: They think we can be addicted to phones.
error: the
error_type: Determiner Error
error_severity: 2
error_description: Determiner Error: According to English grammar rules, the definite article 〈the〉 indicates specificity, but it is not needed when referring to something in a general sense; therefore, the original phrase 〈the phones〉 is changed to 『phones』 to comply with grammatical rules.
error_sentence: Furthermore, if we spend too much time on it, our grades will fall behind.

correct_sentence: Furthermore, if we spend too much time on them, our grades will fall behind.

error: it
correction: them
error_type: Pronoun Error
error_severity: 2
error_description: Pronoun Error: According to English grammar rules, the pronoun 『them』 should be used for plural nouns; in the original sentence, 『phones』 is a plural noun, so the subsequent pronoun should be in the plural form 『them』 to maintain number agreement, thus 〈it〉 needs to be changed to 『them』 to comply with English grammar.
error_sentence: We should use it at the school.
correct_sentence: We should use them at school.
error: it at the
correction: them at
error_type: Pronoun Error
error_severity: 4
error_description: ① Pronoun Error: According to English grammar rules, the pronoun 『them』 should be used for plural nouns; in the original sentence, 『phones』 is a plural noun, so the subsequent pronoun should be in the plural form 『them』 to maintain number agreement, thus 〈it〉 needs to be changed to 『them』 to comply with English grammar; ② Determiner Error: According to English grammar rules, the definite article 〈the〉 indicates specificity, but it is not needed when referring to a school in a general sense; therefore, the original phrase 〈at the school〉 is changed to 『at school』 to comply with grammatical rules.
error_sentence: But we mustn't use it at class.
correct_sentence: But we mustn't use them in class.
error: it at
correction: them in
error_type: Pronoun Error
error_severity: 4
error_description: ① Pronoun Error: According to English grammar rules, the pronoun 『them』 should be used for plural nouns; in the original sentence, 『phones』 is a plural noun, so the subsequent pronoun should be in the plural form 『them』 to maintain number agreement, thus 〈it〉 needs to be changed to 『them』 to comply with English grammar; ② Preposition Error: According to English idiomatic expressions, the preposition 『In』 is used to mean “inside...”; therefore, the original phrase 〈at class〉 should be changed to 『in class』 to conform to idiomatic usage.
error_sentence: It is wonderful for us, if we use it right.
correct_sentence: It is wonderful for us if we use them right.
error: ,
error_type: Punctuation Error
error_severity: 2
error_description: Punctuation Error: According to English idiomatic expressions, a comma is not needed before the adverbial clause 〈if we use them right〉; therefore, the comma 〈,〉 is deleted to make the sentence structure more concise and to comply with punctuation rules for complex sentences.
error_sentence: It is wonderful for us, if we use it right.
correct_sentence: It is wonderful for us if we use them right.
error: it
correction: them
error_type: Pronoun Error
error_severity: 2
error_description: Pronoun Error: According to English grammar rules, the pronoun 『them』 should be used for plural nouns; in the original sentence, 『cellphones』 is a plural noun, so the subsequent pronoun should be in the plural form 『them』 to maintain number agreement, thus 〈it〉 needs to be changed to 『them』 to comply with English grammar.