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 Store is having a sale, and it is very preferential. There are all kinds of sweater here, and it costs only thirty dollars. The shorts are only 20 yuan. Beautiful shirts are only 25 yuan. Big bags are 30 yuan and small bags are 20 yuan. And there are lots of beautiful shoes and dresses. Welcome to Choose and Buy.

Corrected essay:
Mr. Cool's Clothes Store is having a sale, and it is very preferential. There are all kinds of sweaters here, and they cost only thirty yuan. The shorts are only 20 yuan. Beautiful shirts are only 25 yuan. Big bags are 30 yuan and small bags are 20 yuan. And there are lots of beautiful shoes and dresses. Welcome to choose and buy.

Error analysis:
error_sentence: There are all kinds of sweater here, and it costs only thirty dollars.
correct_sentence: There are all kinds of sweaters here, and they cost only thirty yuan.
error: sweater
correction: sweaters
error_type: Noun Number Error
error_severity: 2
error_description: Noun Number Error: According to English grammar rules, 〈all kinds of〉 should be followed by a plural noun to indicate multiple types of items; in the original sentence, 〈sweater〉 should be in plural form, therefore 〈sweater〉 should be changed to 『sweaters』 to comply with English grammar rules.

error_sentence: There are all kinds of sweater here, and it costs only thirty dollars.
correct_sentence: There are all kinds of sweaters here, and they cost only thirty yuan.
error: it costs
correction: they cost
error_type: Pronoun Error
error_severity: 3
error_description: Pronoun Error: According to English grammar rules, the pronoun 『they』 should be used for plural nouns; in the original sentence, 〈sweaters〉 is a plural noun, so the subsequent pronoun should be the plural form 『they』 to maintain number agreement. Therefore, the subject 〈it〉 and the verb 〈costs〉 need to be changed to the plural pronoun 『they』 and the corresponding verb form 『cost』 to comply with English grammar.

error_sentence: There are all kinds of sweater here, and it costs only thirty dollars.
correct_sentence: There are all kinds of sweaters here, and they cost only thirty yuan.
error: dollars
correction: yuan
error_type: Noun Error
error_severity: 3
error_description: Noun Error: According to the prompt requirements, the meaning here is “30 yuan”; the original context uses the RMB unit, therefore the US dollar unit 〈dollars〉 needs to be changed to 『yuan』 to ensure semantic accuracy.

error_sentence: Welcome to Choose and Buy.
correct_sentence: Welcome to choose and buy.
error: Choose and Buy
correction: choose and buy
error_type: Case Error
error_severity: 1
error_description: Case Error: According to English writing conventions, words not at the beginning of a sentence do not need to be capitalized; in the original sentence, 〈Choose and Buy〉 is not at the beginning of the sentence and does not need to be capitalized, therefore 〈Choose and Buy〉 needs to be changed to 『choose and buy』 to conform to conventions.