Writing prompt: Using the given vocabulary and sentence patterns, and referring to the picture, write a short essay. It is 3 PM. Based on the information provided below about Linda, use the present continuous tense to describe what Linda sees and hears at the mall:
Writing hints:
A little girl: buy some food
A young lady: look at a dress
Linda's mother: try on the shoes
Linda's father: stay on the sofa; wait for

Student essay:
At the shop, A little girl are buy some food. A young lady is look at a dress. My mother is try the shoes. My fatner is stay on the sofa

Corrected essay:
At the shop, a little girl is buying some food. A young lady is looking at a dress. My mother is trying on the shoes. My father is staying on the sofa.

Error analysis:
error_sentence: At the shop, A little girl are buy some food.
correct_sentence: At the shop, a little girl is buying some food.
error: A
correction: a
error_type: Case Error
error_severity: 1
error_description: Case Error: According to English writing conventions, when 〈A little girl〉 appears in the middle of a sentence and not at the beginning, its initial letter 〈A〉 should be lowercase. Therefore, the capitalized determiner 〈A〉 is changed to the lowercase form 『a』, making the entire noun phrase 『a little girl』 conform to the standard writing rules for common noun phrases not at the beginning of a sentence.

error_sentence: At the shop, A little girl are buy some food.
correct_sentence: At the shop, a little girl is buying some food.
error: are buy
correction: is buying
error_type: Verb Tense Error
error_severity: 3
error_description: ① Subject-Verb Agreement Error: According to English grammar rules, when the subject “a little girl” is a third-person singular noun, the verb should be in the singular form. The incorrect use of the plural verb 〈are〉 was detected, so it is changed to the singular form 『is』 to maintain subject-verb agreement; ② Verb Tense Error: According to the structure requirement of the present continuous tense (be verb + present participle), the original sentence incorrectly uses the base form verb 〈buy〉; it should be changed to the present participle form 『buying』 to form the complete continuous structure 『is buying』, accurately expressing an ongoing action.

error_sentence: A young lady is look at a dress.
correct_sentence: A young lady is looking at a dress.
error: look
correction: looking
error_type: Nonfinite Verb Form Error
error_severity: 3
error_description: Nonfinite Verb Form Error: According to English grammar rules, the present continuous tense should use the compound structure “be verb + present participle”. The original sentence uses the base form verb 〈look〉, which does not meet the requirement for the continuous tense, so it is changed to the present participle form 『looking』, forming the complete continuous structure “be looking”, which aligns with the grammatical function of the present continuous tense to express an “ongoing action”.

error_sentence: My mother is try the shoes.
correct_sentence: My mother is trying on the shoes.
error: try
correction: trying on
error_type: Nonfinite Verb Form Error
error_severity: 3
error_description: ① Nonfinite Verb Form Error: According to the formation rules of the present continuous tense in English grammar (be verb + present participle), the original sentence incorrectly uses the base form verb 〈try〉; it should be changed to the present participle form 『trying』 to form the correct continuous tense structure. This modification ensures the accurate expression of the meaning “is trying”; ② Preposition Error: According to English fixed phrase usage, “try on” is the phrasal verb meaning “to test clothing by putting it on”, where the preposition 『on』 cannot be omitted. Therefore, the complete phrasal structure 『trying on』 is retained to conform to the standard expression of this phrase.

error_sentence: My fatner is stay on the sofa
correct_sentence: My father is staying on the sofa.
error: fatner is stay
correction: father is staying
error_type: Nonfinite Verb Form Error
error_severity: 3
error_description: ① Spelling Error: According to English spelling rules, 〈fatner〉 does not conform to the morphology of any English word. Based on the context, it should refer to the family member “father”, so it is corrected to the proper spelling 『father』; ② Nonfinite Verb Form Error: According to the grammatical structure requirement of the present continuous tense (be verb + present participle), the original sentence incorrectly uses the base form verb 〈stay〉. It should be changed to the present participle form 『staying』 to form the standard continuous tense, thus accurately expressing the continuous meaning of “is staying/residing”. It must also ensure correct subject-verb agreement with the be verb (is/am/are).

error_sentence: My fatner is stay on the sofa
correct_sentence: My father is staying on the sofa.
correction: .
error_type: Punctuation Error
error_severity: 2
error_description: Punctuation Error: According to standard English writing rules, a complete declarative sentence must end with a terminal punctuation mark (period 『.』). The current sentence was detected to be missing the ending punctuation, so a period 『.』 is added to comply with English writing conventions.