Writing prompt: Using the given vocabulary and sentence patterns, and referring to the picture, write a short essay. It is currently 7 PM. Based on the information provided by Linda below, use the present continuous tense to describe what Linda and her family are doing. Writing hints: Linda: help mother do housework; grandparents: watch TV; brother: play computer games; mother: cook; sister: listen to the radio.

Student essay:
At 7. pm. Linda and her parents at home. Linda helps her mother do her housework. Her grandparents are watching TV now. Her brother is playing computer games now. Linda's mother is cooking now. Her sister is listening to the radio now. They are so happy!

Corrected essay:
At 7 p.m., Linda and her family are at home. Linda is helping her mother do the housework. Her grandparents are watching TV now. Her brother is playing computer games now. Linda's mother is cooking now. Her sister is listening to the radio now. They are so happy!

Error analysis:
error_sentence: At 7. pm.
correct_sentence: At 7 p.m., Linda and her family are at home.
error: . pm.
correction: p.m.,
error_type: Punctuation Error
error_severity: 3
error_description: ① Punctuation Error: According to English time expression norms, a period should not be used between the number and the time abbreviation. The period 〈.〉 after the number 7 in the original expression 〈7. pm.〉 is redundant and should be deleted, keeping it as 『7 pm.』; ② Punctuation Error: According to standard English format, when the Latin abbreviation 〈pm〉 indicates "afternoon", a period should follow each letter without a space between them. Therefore, 〈pm.〉 needs to be changed to the standard abbreviation form 『p.m.』; ③ Punctuation Error: According to English grammar rules, when a time adverbial is placed at the beginning of a sentence, it should be separated from the main clause by a comma. The original sentence lacks the necessary comma pause; a comma should be added after the time adverbial 『At 7 p.m.』 to form the correct structure 『At 7 p.m., Linda and her family are at home.』.
error_sentence: Linda and her parents at home.
correct_sentence: At 7 p.m., Linda and her family are at home.
error: parents
correction: family are
error_type: Sentence Structure Error
error_severity: 4
error_description: ① Noun Error: Based on the family members described in the prompt (grandparents, parents, brother, etc.), 〈parents〉 only refers to the limited scope of "mother and father" and cannot fully cover all kinship relations. According to the semantic scope of English family terms, the collective noun 『family』 should be used, changing it to 『Linda and her family』 to accurately express the complete family unit including multiple generations; ② Sentence Structure Error: According to basic English sentence patterns, the subject 〈Linda and her family〉, as a plural entity, must be paired with a linking verb to form a complete subject-verb-complement structure. The original sentence lacks the necessary predicate component; the plural linking verb 『are』 needs to be added to form the predicate structure 『are at home』, ensuring the sentence meets the basic "subject + linking verb + complement" pattern requirement.
error_sentence: Linda helps her mother do her housework.
correct_sentence: Linda is helping her mother do the housework.
error: helps
correction: is helping
error_type: Verb Tense Error
error_severity: 3
error_description: Verb Tense Error: According to the present continuous tense context required by the prompt, the original sentence 〈helps〉 uses the simple present tense, which does not match the requirement to describe an action currently in progress. Based on the rules for forming the English continuous tense, the verb needs to be changed to the 『is helping』 structure, forming the correct present continuous expression 『Linda is helping her mother』 to accurately reflect the immediacy of the action.
error_sentence: Linda helps her mother do her housework.
correct_sentence: Linda is helping her mother do the housework.
error: her
correction: the
error_type: Determiner Error
error_severity: 2
error_description: Determiner Error: As an uncountable noun, 〈housework〉 usually does not require possessive modification when referring to housework in general. The original phrase 〈her housework〉 inappropriately limits the scope of ownership of the housework, whereas the context actually emphasizes the objective existence of household chores. According to the usage rules for English uncountable nouns, the definite article 〈the〉 should be used to specify the housework in the current family setting, correcting it to 『do the housework』 to maintain semantic objectivity.