Writing prompt: Based on the given hints and referring to the picture, write a short essay.
Last Sunday, I went for a picnic in the park with my friends. It started raining in the afternoon. I forgot my umbrella and got wet. I felt cold and had a headache. My friends took me to the hospital. The doctor said I had a fever. He gave me some medicine and told me to go home and rest well.
Writing hints: picnic; rain; umbrella; get wet; hospital; fever; medicine.

Student essay:
Last Sunday. I and my friend go on a picnic in the park. In afternoon is rainy. I haven't got umbrella. I wet. I feel very cold and headache.

Corrected essay:
Last Sunday, my friends and I went on a picnic in the park. In the afternoon, it was rainy. I didn't have an umbrella. I got wet. I felt very cold and had a headache.

Error analysis:
error_sentence: Last Sunday. I and my friend go on a picnic in the park.
correct_sentence: Last Sunday, my friends and I went on a picnic in the park.
error: . I and my friend go
correction: , my friends and I went
error_type: Word Order Error
error_severity: 5
error_description: ① Punctuation Error: 〈Last Sunday〉 is a time adverbial and should be followed by a comma, not a period, when preceding the main clause; change 〈.〉 to 『,』.; ② Word Order Error: English convention places others before 'I' for politeness; change 〈I and my friend〉 to 『my friends and I』.; ③ Noun Number Error: The prompt implies plural friends, so the singular noun 〈my friend〉 should be changed to the plural 『my friends』.; ④ Verb Tense Error: The context describes a past event, requiring the simple past tense; change the verb 〈go〉 to its past form 『went』.

error_sentence: In afternoon is rainy.
correct_sentence: In the afternoon, it was rainy.
error: afternoon is
correction: the afternoon, it was
error_type: Verb Tense Error
error_severity: 5
error_description: ① Determiner Error: The fixed phrase is 'in the afternoon', requiring the definite article 『the』 before 〈afternoon〉.; ② Punctuation Error: When the time adverbial 『In the afternoon』 starts a sentence, it should be followed by a comma 『,』.; ③ Pronoun Error: The prepositional phrase 〈In afternoon〉 cannot be the subject; the sentence lacks a subject. Add the formal subject 『it』 before 〈is〉.; ④ Verb Tense Error: The context is past tense, so the verb 〈is〉 should be changed to its past form 『was』.

error_sentence: I haven't got umbrella.
correct_sentence: I didn't have an umbrella.
error: haven't got
correction: didn't have an
error_type: Verb Choice Error
error_severity: 5
error_description: ① Verb Tense Error: Describing a past event requires the simple past tense; change the present perfect 〈haven't got〉 to the simple past 『didn't have』.; ② Verb Choice Error: 'have got' is present tense and cannot be negated with 『didn't』; change 〈haven't got〉 to 『didn't have』.; ③ Determiner Error: The singular countable noun 〈umbrella〉 requires the indefinite article 『an』.

error_sentence: I wet.
correct_sentence: I got wet.
correction: got
error_type: Verb Choice Error
error_severity: 3
error_description: Verb Choice Error: The intended meaning is 'I got wet', but the sentence lacks a predicate verb; add 『got』 to form the structure 〈get wet〉 for a complete sentence according to English syntax.

error_sentence: I feel very cold and headache.
correct_sentence: I felt very cold and had a headache.
error: feel
correction: felt
error_type: Verb Tense Error
error_severity: 3
error_description: Verb Tense Error: The context indicates a past event, requiring the simple past tense; change the simple present verb 〈feel〉 to the simple past 『felt』 to match the tense.

error_sentence: I feel very cold and headache.
correct_sentence: I felt very cold and had a headache.
correction: had a
error_type: Verb Choice Error
error_severity: 5
error_description: ① Verb Choice Error: The fixed phrase is 'have a headache'; the verb 'have' is missing. The context requires the past tense, so add 『had a』 before 〈headache〉 to form a complete verb-object structure and match the tense.; ② Determiner Error: The countable noun 〈headache〉 requires the indefinite article 『a』 as per grammar rules and the fixed phrase.