Writing prompt: Using the information provided in Chinese and referring to the picture, write a short essay.
Mr. Cool's Clothes Store is having a big sale with great discounts. Sweaters in various colors are only 30 yuan, shorts are only 20 yuan, and shirts are only 25 yuan. Large bags sell for 35 yuan, and small bags for 20 yuan. There are also many beautiful shoes and skirts available. Welcome to shop.

Student essay:
Mr. Cool's Clothes shop there is a big sale, very favorable. Sweaters of various colors are only sold in 30 yuan , shorts are only sold in 20 yuan, Shirts are compact in 25 yuan, with big bags selling for five yuan and small bags selling for 20 yuan. There are many beautiful shoes and skirts, and you are welcome to come and buy them.

Corrected essay:
Mr. Cool's Clothes shop is having a big sale, which is very favorable. Sweaters of various colors are only sold for 30 yuan, shorts are only sold for 20 yuan, and shirts are priced at 25 yuan, with big bags selling for 35 yuan and small bags selling for 20 yuan. There are many beautiful shoes and skirts, and you are welcome to come and buy them.

Error analysis:
error_sentence: Mr. Cool's Clothes shop there is a big sale, very favorable.
correct_sentence: Mr. Cool's Clothes shop is having a big sale, which is very favorable.
error: there is
correction: is having
error_type: Sentence Structure Error
error_severity: 4
error_description: Sentence Structure Error: According to English expression habits, the existential sentence 〈there is〉 cannot accurately describe a promotional activity actively carried out by the store; using the present continuous tense 『is having』 can more accurately express the ongoing sales action of the store, therefore the original sentence 〈there is〉 needs to be changed to 『is having』 to meet the contextual requirements.

error_sentence: Mr. Cool's Clothes shop there is a big sale, very favorable.
correct_sentence: Mr. Cool's Clothes shop is having a big sale, which is very favorable.
correction: which is
error_type: Sentence Structure Error
error_severity: 4
error_description: Sentence Structure Error: According to English grammar rules, the adjective phrase 〈very favorable〉 as an isolated component requires a relative pronoun to form an adjective clause. Adding 『which is』 connects the two independent clauses into a compound sentence, making the sentence structure complete and conforming to formal written expression standards. Therefore, 〈very favorable〉 is modified to 『which is very favorable』 to meet English syntactic requirements.

error_sentence: Sweaters of various colors are only sold in 30 yuan , shorts are only sold in 20 yuan, Shirts are compact in 25 yuan, with big bags selling for five yuan and small bags selling for 20 yuan.
correct_sentence: Sweaters of various colors are only sold for 30 yuan, shorts are only sold for 20 yuan, and shirts are priced at 25 yuan, with big bags selling for 35 yuan and small bags selling for 20 yuan.
error: in
correction: for
error_type: Preposition Error
error_severity: 2
error_description: Preposition Error: According to English expression habits, the preposition 〈in〉 is not suitable for indicating transactions involving amounts of money; the preposition in 〈sold in〉 in the original sentence is incorrect, therefore 〈sold in〉 is modified to 『sold for』 to conform to English expression habits.

error_sentence: Sweaters of various colors are only sold in 30 yuan , shorts are only sold in 20 yuan, Shirts are compact in 25 yuan, with big bags selling for five yuan and small bags selling for 20 yuan.
correct_sentence: Sweaters of various colors are only sold for 30 yuan, shorts are only sold for 20 yuan, and shirts are priced at 25 yuan, with big bags selling for 35 yuan and small bags selling for 20 yuan.
error: in
correction: for
error_type: Preposition Error
error_severity: 2
error_description: Preposition Error: According to English expression habits, the preposition 〈in〉 is not suitable for indicating transactions involving amounts of money; the preposition in 〈sold in〉 in the original sentence is incorrect, therefore 〈sold in〉 is modified to 『sold for』 to conform to English expression habits.

error_sentence: Sweaters of various colors are only sold in 30 yuan , shorts are only sold in 20 yuan, Shirts are compact in 25 yuan, with big bags selling for five yuan and small bags selling for 20 yuan.
correct_sentence: Sweaters of various colors are only sold for 30 yuan, shorts are only sold for 20 yuan, and shirts are priced at 25 yuan, with big bags selling for 35 yuan and small bags selling for 20 yuan.
error: Shirts are compact in
correction: and shirts are priced at
error_type: Conjunction Error
error_severity: 5
error_description: ① Conjunction Error: According to English grammar rules, in the original sentence, 〈shorts are only sold in 20 yuan〉 and 〈Shirts are compact in 25 yuan〉 have complete subject-verb structures; as parallel items, they need to be connected by 『and』 to conform to English grammar rules; ② Verb Choice Error: According to the context, the sentence here means "priced"; in the original sentence, 〈compact〉 indicates a physical compressed state, which does not fit the meaning, therefore 〈compact〉 needs to be changed to 『priced』 to fit the context; ③ Preposition Error: According to the context, the sentence here means "priced"; 『priced at』 is a fixed collocation, therefore 〈in〉 in the original sentence needs to be changed to 『at』.

error_sentence: Sweaters of various colors are only sold in 30 yuan , shorts are only sold in 20 yuan, Shirts are compact in 25 yuan, with big bags selling for five yuan and small bags selling for 20 yuan.
correct_sentence: Sweaters of various colors are only sold for 30 yuan, shorts are only sold for 20 yuan, and shirts are priced at 25 yuan, with big bags selling for 35 yuan and small bags selling for 20 yuan.
error: five
correction: 35
error_type: Number Error
error_severity: 2
error_description: Number Error: According to the requirements of the prompt, this should be "35 yuan"; therefore, 〈five〉 in the original sentence incorrectly represents the price of the large bags and should be modified to 『35』 to conform to the information given in the question.