Writing prompt: My Free Time

Student essay:
I have many hobby.My favourite is basketball,so I often play basketball in my free time.And I like football too,because I play it is very wonderful.In my free time.I often listen to music.I have a good friend.He like basketball and football,too.So we often play sports in free time.I very happy in my free time.

Corrected essay:
I have many hobbies. My favourite is basketball, so I often play basketball in my free time. And I like football too, because playing it is very wonderful. In my free time, I often listen to music. I have a good friend. He likes basketball and football, too. So we often play sports in free time. I am very happy in my free time.

Error analysis:
error_sentence: I have many hobby.
correct_sentence: I have many hobbies.
error: hobby
correction: hobbies
error_type: Noun Number Error
error_severity: 2
error_description: Noun Number Error: According to English grammar rules, when the determiner 〈many〉 modifies a countable noun, it requires the plural form. Therefore, the singular noun 〈hobby〉 is changed to its plural form 『hobbies』 to conform to the consistency of quantity expression.
error_sentence: And I like football too,because I play it is very wonderful.
correct_sentence: And I like football too, because playing it is very wonderful.
error: I play
correction: playing
error_type: Sentence Structure Error
error_severity: 3
error_description: ① Word Redundancy Error: The original sentence 〈I play it is very wonderful〉 has structural redundancy and does not conform to English complex sentence norms. According to the sentence meaning, the redundant subject needs to be deleted, and the main clause 〈I play it〉 should be changed to the gerund phrase 『playing it』, deleting the redundant subject, making it the subject of the adverbial clause of reason introduced by 〈because〉, forming a logically coherent complex sentence structure; ② Nonfinite Verb Form Error: According to English grammar rules, the verb 〈play〉 in the clause needs to be changed to the gerund 『playing』 to serve as the subject of the adverbial clause of reason introduced by 〈because〉, making the sentence clearer and more fluent after modification.
error_sentence: In my free time.
correct_sentence: In my free time, I often listen to music.
error: .
correction: ,
error_type: Punctuation Error
error_severity: 2
error_description: Punctuation Error: According to English punctuation rules, 〈In my free time.〉 as an adverbial component cannot stand alone as a sentence. Therefore, the period at the end of the sentence is changed to a comma, connecting it with the main clause 〈I often listen to music〉 to form a complete complex sentence structure.
error_sentence: He like basketball and football,too.
correct_sentence: He likes basketball and football, too.
error: like
correction: likes
error_type: Subject-Verb Agreement Error
error_severity: 3
error_description: Subject-Verb Agreement Error: The subject 〈He〉 is in the third-person singular form. According to the English subject-verb agreement principle, the predicate verb needs to be in the singular form. Therefore, the original verb 〈like〉 is changed to its third-person singular form 『likes』 to ensure grammatical correctness.
error_sentence: I very happy in my free time.
correct_sentence: I am very happy in my free time.
correction: am
error_type: Verb Choice Error
error_severity: 3
error_description: Verb Choice Error: The adjective phrase 〈very happy〉 needs to be paired with a linking verb to form a complete predicate structure. According to basic English sentence pattern rules, the linking verb 『am』 is added after the subject 〈I〉, forming the correct subject-linking verb-predicative structure 『I am very happy』, making the sentence conform to grammatical norms.