Writing prompt: The weekend is coming. Classmates, what are you planning to do? Using the given vocabulary and sentence patterns, and referring to the picture, write a short essay of about 60 words about your plans for the weekend.
Writing hints: be going to; do cleaning; visit grandparents; have a good time

Student essay:
Weekend is coming. I an going to do cleaning, because my home is drity. I also going to the visit grandparents. I have a good time.

Corrected essay:
Weekend is coming. I am going to do cleaning, because my home is dirty. I am also going to visit my grandparents. I will have a good time.

Error analysis:
error_sentence: I an going to do cleaning, because my home is drity.
correct_sentence: I am going to do cleaning, because my home is dirty.
error: an
correction: am
error_type: Spelling Error
error_severity: 2
error_description: Spelling Error: According to the sentence meaning, the original sentence uses a 'subject-verb-object' structure here; it can be seen that 〈an〉 is a spelling error for the first-person form 『am』 of the linking verb 'be', thus it needs to be corrected to 『am』 to fit the correct contextual meaning.

error_sentence: I an going to do cleaning, because my home is drity.
correct_sentence: I am going to do cleaning, because my home is dirty.
error: drity
correction: dirty
error_type: Spelling Error
error_severity: 2
error_description: Spelling Error: According to the sentence meaning, 〈drity〉 in the original text intends to express 'dirty', therefore 〈drity〉 is a spelling error and needs to be corrected to 『dirty』 to fit the correct contextual meaning.

error_sentence: I also going to the visit grandparents.
correct_sentence: I am also going to visit my grandparents.
correction: am
error_type: Auxiliary Error
error_severity: 3
error_description: Auxiliary Error: According to English grammar rules and the prompt words, the tense of the original text is present continuous, with the complete structure being 〈be going to〉. Therefore, 〈I also going to the visit grandparents〉 needs to be corrected to 『I am also going to visit my grandparents』 to conform to the correct present continuous structure.

error_sentence: I also going to the visit grandparents.
correct_sentence: I am also going to visit my grandparents.
error: the visit
correction: visit my
error_type: Pronoun Error
error_severity: 3
error_description: ① Determiner Error: According to English grammar rules, 〈visit〉 in the original sentence is a verb and does not require the determiner 〈the 〉, thus it should be deleted; ② Pronoun Error: According to the original sentence meaning, the possessive relationship for 〈grandparents〉 is missing; therefore, 『my』 should be added, correcting it to 『visit my』 to make the meaning clear.

error_sentence: I have a good time.
correct_sentence: I will have a good time.
correction: will
error_type: Verb Tense Error
error_severity: 4
error_description: Verb Tense Error: According to English grammar rules and the composition prompt words, the original text is a short essay describing weekend plans, and the sentence should be in the future tense. Therefore, 〈I have a good time〉 is a verb tense error and needs to be corrected to 『I will have a good time』 to conform to the correct future tense structure.