Writing prompt: Dear Professor Frank Jason

Student essay:
I am Z, the chairman of the Student Union of Y High School. I'm writing to invite you to give a lecture about how to improve our English writing.
Recently, we carried out some examinations and the result shows that we have a great deal of problems on English writing, and thus I want to invite you to give us some useful advice. For example, most of the students could do nothing but simply put the events in order. Besides, they have no idea on how to decorate their words and sentences which can improve their marks.
As a result, we decide to hold a lecture in our Lecture Hall next Wednesday. We all agree that you are the best person to be the lecturer. I will be very glad if you can deliver a lecture for us.
Yours
Z

Corrected essay:
I am Z, the chairman of the Student Union of Y High School. I'm writing to invite you to give a lecture about how to improve our English writing.
Recently, we carried out some examinations and the result shows that we have a great deal of problems with English writing, and thus I want to invite you to give us some useful advice. For example, most of the students could do nothing but simply put the events in order. Besides, they have no idea how to decorate their words and sentences which can improve their marks.
As a result, we have decided to hold a lecture in our Lecture Hall next Wednesday. We all agree that you are the best person to be the lecturer. I will be very glad if you can deliver a lecture for us.
Yours,
Z

Error analysis:
error_sentence: Recently, we carried out some examinations and the result shows that we have a great deal of problems on English writing, and thus I want to invite you to give us some useful advice.
correct_sentence: Recently, we carried out some examinations and the result shows that we have a great deal of problems with English writing, and thus I want to invite you to give us some useful advice.
error: on
correction: with
error_type: Preposition Error
error_severity: 2
error_description: Preposition Error: The correct collocation is “have problems with something”, therefore 〈on〉 needs to be changed to 『with』 to comply with fixed collocation rules.
error_sentence: Besides, they have no idea on how to decorate their words and sentences which can improve their marks.

correct_sentence: Besides, they have no idea how to decorate their words and sentences which can improve their marks.

error: on
error_sentence: As a result, we decide to hold a lecture in our Lecture Hall next Wednesday.
correct_sentence: As a result, we have decided to hold a lecture in our Lecture Hall next Wednesday.
error: decide
correction: have decided
error_type: Verb Tense Error
error_severity: 3
error_description: Verb Tense Error: According to the contextual time logic, the present perfect tense should be used here to emphasize the impact of a past action on the present (the decision has been made and continues to the present), therefore 〈decide〉 needs to be changed to 『have decided』 to comply with grammatical rules.
error_sentence: Yours
Z
correct_sentence: Yours,
Z
correction: ,
error_type: Punctuation Error
error_severity: 2
error_description: Punctuation Error: After the closing salutation 〈Yours〉 in an English letter, a comma must be added to separate 〈Yours〉 and 〈Z〉, therefore a 『,』 is added after 〈Yours〉 to comply with letter format conventions.