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, My friends and I were going to park for a picnic. It's rain. We don't bring umberlla. We got wet. We going to the hospital. The doctor said"you are have a fever. "He gave me some medicine.

Corrected essay:
Last Sunday, my friends and I went to the park for a picnic. It's rainy. We didn't bring umbrellas. We got wet. We went to the hospital. The doctor said, "You have a fever." He gave me some medicine.

Error analysis:
error_sentence: Last Sunday, My friends and I were going to park for a picnic.
correct_sentence: Last Sunday, my friends and I went to the park for a picnic.
error: My
correction: my
error_type: Case Error
error_severity: 1
error_description: Case Error: According to English writing conventions, the first letter of a word at the beginning of a sentence/proper noun needs to be capitalized; in the original sentence, 〈My〉 is not at the beginning of the sentence and should be in lowercase form, so it needs to be changed to 『my』 to conform to the convention.
error_sentence: Last Sunday, My friends and I were going to park for a picnic.
correct_sentence: Last Sunday, my friends and I went to the park for a picnic.
error: were going to
correction: went to the
error_type: Verb Tense Error
error_severity: 3
error_description: ① Verb Tense Error: According to the context, the sentence "Last Sunday" describes a past event, while the original phrase 〈were going to〉 is in the past continuous tense; it needs to be changed to the simple past tense 『went to』 to fit the context; ② Determiner Error: According to English expression habits, 〈park〉 is a specific place, so 『the』 needs to be added before 〈park〉 to specify the park.
error_sentence: It's rain.
correct_sentence: It's rainy.
error: rain
correction: rainy
error_type: PoS Confusion Error
error_severity: 3
error_description: PoS Confusion Error: According to English grammar rules, the linking verb 〈is〉 should be followed by an adjective as a predicative, but the original word 〈rain〉 is a noun; therefore, it needs to be changed to the adjective 『rainy』 to conform to grammatical rules.
error_sentence: We don't bring umberlla.
correct_sentence: We didn't bring umbrellas.
error: do
correction: did
error_type: Verb Tense Error
error_severity: 3
error_description: Verb Tense Error: According to the context, "Last Sunday" describes a past event, while the original 〈don't〉 is in the simple present tense; it needs to be changed to the simple past tense 『didn't』 to fit the context.
error_sentence: We don't bring umberlla.
correct_sentence: We didn't bring umbrellas.
error: umberlla
correction: umbrellas
error_type: Noun Number Error
error_severity: 3
error_description: ① Spelling Error: According to the sentence meaning, the intention is to express "umbrellas," so 〈umberlla〉 is a misspelling of 『umbrellas』; it needs to be changed to 『umbrellas』 to make the sentence coherent; ② Noun Number Error: According to the context, when 〈umberlla〉 appears alone in the original sentence without a determiner, it needs to be in the plural form; it should be changed to 『umbrellas』 to conform to English expression habits.
error_sentence: We going to the hospital.
correct_sentence: We went to the hospital.
error: going
correction: went
error_type: Verb Tense Error
error_severity: 3
error_description: Verb Tense Error: According to the context, the sentence "Last Sunday" describes a past event, while the original 〈going〉 is in the progressive form; it needs to be changed to the simple past tense 『went』 to fit the context.
error_sentence: The doctor said"you are have a fever.
correct_sentence: The doctor said, "You have a fever."
error: said"you are
correction: said, "You
error_type: Word Redundancy Error
error_severity: 4
error_description: ① Punctuation Error: According to English writing conventions, a comma is needed before direct speech to separate the main clause from the quote, so 〈said"〉 should be changed to 『said, "』 to conform to English writing conventions; ② Case Error: According to English written expression conventions, the first letter of the word at the beginning of a sentence needs to be capitalized, so 〈you〉 needs to be changed to 『You』; ③ Word Redundancy Error: According to English grammar rules, the original phrase 〈are have〉 contains a redundant linking verb; the verb 'be' used alone means "is/exists", so 〈are〉 should be deleted and changed to 『You have』 to conform to English grammar.