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 very cheap now. Sweaters of all colors only need 30 yuan. 20 yuan in shorts. 25 yuan in T-shirt. Big bag is 35 yuan and small bag is 20 yuan. And there are so many shoes and dresses in there. Welcome to Mr. Cool's Clothes Store.

Corrected essay:
Mr. Cool's Clothes Store is very cheap now. Sweaters of all colors only sell for 30 yuan. Shorts sell for 20 yuan. T-shirts sell for 25 yuan. Big bags sell for 35 yuan and small bags sell for 20 yuan. And there are so many shoes and dresses there. Welcome to Mr. Cool's Clothes Store.

Error analysis:
error_sentence: Mr. cool's Clothes Store is very cheap now.
correct_sentence: Mr. Cool's Clothes Store is very cheap now.
error: cool
correction: Cool
error_type: Case Error
error_severity: 1
error_description: Case Error: The prompt clearly states the store name 『Mr. Cool's Clothes Store』. As a proper noun, the first letter of 『cool』 should be capitalized to match the store name in the prompt and follow the rules for proper nouns. Therefore, the correct form should be 『Mr. Cool's』. This modification adheres to the writing conventions for proper nouns.

error_sentence: Sweaters of all colors only need 30 yuan.
correct_sentence: Sweaters of all colors only sell for 30 yuan.
error: need
correction: sell for
error_type: Verb Choice Error
error_severity: 3
error_description: Verb Choice Error: The verb 〈need〉 indicates demand rather than the price of goods, which does not fit the sentence context. 〈sell for〉 should be used to indicate the selling price of the goods. Therefore, changing 〈need〉 to 『sell for』 more accurately describes the product price and fits the semantics.

error_sentence: Sweaters of all colors only need 30 yuan. 20 yuan in shorts.
correct_sentence: Shorts sell for 20 yuan.
correction: Shorts sell for
error_type: Sentence Structure Error
error_severity: 4
error_description: Sentence Structure Error: The original phrase 〈20 yuan in shorts〉 lacks a subject and a predicate verb, making the sentence structure incomplete and unable to clearly express the meaning. To make it a complete sentence conforming to English grammatical norms, a subject and predicate verb need to be added. By adding 『Shorts sell for』, a complete subject-verb structure can be formed, resulting in the sentence 『Shorts sell for 20 yuan』. This modification not only corrects the sentence grammar but also clearly conveys the meaning 'shorts sell for 20 yuan', meeting the basic structural requirements of an English declarative sentence.

error_sentence: 20 yuan in shorts. 25 yuan in T-shirt.
correct_sentence: Shorts sell for 20 yuan.
error: in shorts. 25 yuan in
correction: .
error_type: Sentence Redundancy Error
error_severity: 4
error_description: Sentence Redundancy Error: Other modifications here have already changed the sentence to the correct 'Shorts sell for 20 yuan.' and 'T-shirts sell for 25 yuan.', fully expressing the meaning 'shorts sell for 20 yuan, shirts 25 yuan', so directly replacing 〈in shorts. 25 yuan in〉 with 『.』 here ensures sentence fluency.

error_sentence: 25 yuan in T-shirt.
correct_sentence: T-shirts sell for 25 yuan.
error: shirt
correction: shirts sell for 25 yuan
error_type: Sentence Structure Error
error_severity: 5
error_description: ① Sentence Structure Error: The original phrase lacks a subject and predicate verb, resulting in an incomplete sentence. To express the meaning 'a certain product sells for a certain price', the subject-verb structure 『sell for』 needs to be added to form a grammatically correct complete sentence; ② Noun Number Error: The product name 〈T-shirt〉 here represents a category of goods, not a single item, so the plural form 『T-shirts』 is needed to accurately express the concept of category.

error_sentence: Big bag is 35 yuan and small bag is 20 yuan.
correct_sentence: Big bags sell for 35 yuan and small bags sell for 20 yuan.
error: bag is
correction: bags sell for
error_type: Verb Choice Error
error_severity: 5
error_description: ① Noun Number Error: 〈Big bag〉 is a singular countable noun form, which usually does not appear alone. The intended meaning here is a general reference to 'big bags', so using the plural form is more appropriate. Therefore, change 〈bag〉 to 『bags』 to represent this category of goods; ② Verb Choice Error: The linking verb 〈is〉 cannot indicate the product pricing and does not fit the sentence context. 『sell for』 should be used to indicate the selling price of the goods. Therefore, changing 〈is〉 to 『sell for』 more accurately describes the product price and fits the semantics.

error_sentence: Big bag is 35 yuan and small bag is 20 yuan.
correct_sentence: Big bags sell for 35 yuan and small bags sell for 20 yuan.
error: bag is
correction: bags sell for
error_type: Verb Choice Error
error_severity: 5
error_description: ① Noun Number Error: When referring to a category of goods rather than a single item, the plural form should be used. Therefore, for the product name 〈bag〉, we need to use the plural form 『bags』 to represent this category of goods; ② Verb Choice Error: The linking verb 〈is〉 cannot indicate the product pricing and does not fit the sentence context. 『sell for』 should be used to indicate the selling price; the subject 'Big bags' is plural, and the predicate verb should also be changed to the plural form 『sell for』 according to the subject change. Therefore, changing 〈is〉 to 『sell for』 more accurately describes the product price and fits the semantics.

error_sentence: And there are so many shoes and dresses in there.
correct_sentence: And there are so many shoes and dresses there.
error: in
error_type: Preposition Error
error_severity: 3
error_description: ① Preposition Error: The adverb of place 〈there〉 in the existential 'there be' sentence pattern does not require a preceding preposition; the preposition 〈in〉 in the sentence is redundant. Deleting it does not affect the sentence meaning, thus removing 〈in〉 enhances the clarity and fluency of the expression.