Writing prompt: My Good Friend

Student essay:
This is my friend Bob. Thirteen biethday is today. Bob's favourite colour is green. Bob likes to play besketball after school. Bob's favourite season is spring. Because he likes flower and flying kites.

Corrected essay:
This is my friend Bob. His thirteenth birthday is today. Bob's favourite colour is green. Bob likes to play basketball after school. Bob's favourite season is spring, because he likes flowers and flying kites.

Error analysis:
error_sentence: Thirteen biethday is today.
correct_sentence: His thirteenth birthday is today.
error: Thirteen biethday
correction: His thirteenth birthday
error_type: Pronoun Error
error_severity: 5
error_description: ① Pronoun Error: According to English grammar rules, the sentence lacks a determiner to indicate possession; the possessive pronoun 『His』 needs to be added at the beginning of the sentence to clearly indicate the referent; ② Number Error: According to English expression norms, age ordinals require ordinal numbers rather than cardinal numbers; therefore, the cardinal number 〈Thirteen〉 is changed to the ordinal number 『thirteenth』 to correctly express 'thirteenth birthday'; ③ Case Error: According to English writing conventions, 〈Thirteen〉 in the sentence, when used as an ordinal number modifying a noun, should not be capitalized; therefore, it is changed to 『thirteenth』 to conform to standard format; ④ Spelling Error: According to English vocabulary spelling rules, 〈biethday〉 has an incorrect letter order; the correct spelling should be 『birthday』 (composed of 'birth' and 'day'), meaning 'birthday'.

error_sentence: Bob likes to play besketball after school.
correct_sentence: Bob likes to play basketball after school.
error: besketball
correction: basketball
error_type: Spelling Error
error_severity: 2
error_description: Spelling Error: According to standard English spelling, the letter order in 〈besketball〉 is incorrect; the correct form is 『basketball』 (note the order of letters 〈s〉 and 〈k〉, and maintain the double 〈l〉 structure), meaning 'basketball'.

error_sentence: Bob's favourite season is spring. Because he likes flower and flying kites.
correct_sentence: Bob's favourite season is spring, because he likes flowers and flying kites.
error: . Because
correction: , because
error_type: Punctuation Error
error_severity: 3
error_description: ① Punctuation Error: According to English grammar rules, an adverbial clause of reason introduced by the subordinating conjunction 〈because〉 cannot stand alone as a sentence; the period needs to be changed to a comma, making it dependent on the main clause to form a complex sentence; ② Case Error: According to English sentence structure rules, when 〈Because〉 acts as a clause introducer and is not at the beginning of the sentence, its first letter should not be capitalized; therefore, it is changed to 『because』 to conform to standard writing conventions.

error_sentence: Because he likes flower and flying kites.
correct_sentence: Bob's favourite season is spring, because he likes flowers and flying kites.
error: flower
correction: flowers
error_type: Noun Number Error
error_severity: 2
error_description: Noun Number Error: According to English fixed collocations, the object 〈flower〉 following the verb 〈likes〉 needs to be in the plural form 『flowers』 to conform to the grammatical rule 'like + plural noun' indicating a generic category.