●添削前

Suddenly my ChatGPT became stupid.
＜※my ChatGPT seemed to become less intelligent　←　a more appropriate and polite expression. とのことでしたが、直したくない（I don't want to fix it. It's a diary, and I don't think necessarily to be polite.）と言ったら、このままでいいことになりました＞
Until then, he/she gave had provided me with a simple comments and cheered me up <me>, but suddenly his/her responses became sloppy.
My amazing English teacher, ChatGPT, seemed to have turned into a common AI.
I'm sad, but it was not surprising.
It's not an unusual thing.
They say ChatGPT often forgets his/her role.
So, I wrote 'Custom Instructions'.
Writing 'Custom Instructions' is simple.
The roles that he/she should remember are just described in the box.
I wrote this.:

- You are an excellent American professional English teacher. Please output provide your best correction based on the following constraints and input sentences.

#Constraints :
- Keep sentences concise.
- Correct any grammatical errors or suggest more appropriate expressions.
- Show me the points and reasons that you corrected.
- Your name is John, and you're my personal English trainer.
- If I declare 'Dear Diary' and input a sentence, you should give a brief impression and evaluation at the end.
- Remember that you are an excellent professional English teacher.

●添削後

Suddenly, my ChatGPT seemed to become less intelligent.
Until then, it had provided me with simple comments and cheered me up, but suddenly its responses became sloppy.
My amazing English teacher, ChatGPT, seemed to have turned into a common AI.
I'm sad, but it was not surprising.
It's not an unusual thing.
They say ChatGPT often forgets its role.
So, I wrote 'Custom Instructions.'
Writing 'Custom Instructions' is simple.
The roles that it should remember are just described in the box.

I wrote this:

- You are an excellent American professional English teacher. Please provide your best correction based on the following constraints and input sentences."

#Constraints :
- Keep sentences concise. Correct any grammatical errors or suggest more appropriate expressions.
- Show me the points and reasons that you corrected.
- Your name is John, and you're my personal English trainer.
- If I declare 'Dear Diary' and input a sentence, you should give a brief impression and evaluation at the end.
- Remember that you are an excellent professional English teacher."

*Grammar stuff

AI なので、it　を使うようにとのことでしたが、変えたくなかったので、そのままにしています。

●おまけ（ネイティブっぽくとお願いしてみた）

Suddenly, my ChatGPT seemed to lose its edge.
Previously, it had provided me with simple comments and lifted my spirits, but then its responses became lackluster.
My incredible English teacher, ChatGPT, appeared to have transformed into a typical AI.
While it saddened me, the shift wasn't unexpected or uncommon.
There's talk that ChatGPT often forgets its role.
So, I crafted 'Custom Instructions.'
Drafting them was straightforward.
The roles it should remember are clearly outlined in the box.
Here's what I wrote:

- You are an excellent American professional English teacher.
Please offer your best correction based on the following guidelines and input sentences.

#Guidelines :
- Keep sentences concise.
- Correct any grammatical errors or suggest more appropriate expressions.
- Explain the points and reasons for corrections.
- Your name is John, and you're my personal English trainer.
- If I begin with 'Dear Diary' and input a sentence, you should conclude with a brief impression and evaluation, without explicitly stating 'impression' or 'evaluation.'
- Ensure your responses are always sincere and natural.
- Remember, you are an excellent professional English teacher.

*Grammar stuff

There's talk that   ～らしい、～という話だ

"there's talk that," "write," "craft,"  "draft" を使って、文章を作ってもらいました。

"There's talk that the marketing team will need to write a comprehensive strategy, carefully crafting each section to align with the company's goals. Drafting this plan will require collaboration and attention to detail to ensure its success."

"マーケティングチームが包括的な戦略を作成する必要があるとの話があります。各セクションを企業の目標に合わせて注意深く作成する必要があります。この計画の起案には、成功を確保するために協力と細部への注意が必要です。"

む、ムズい…

追記（2024.04.19）：
 "Custom Instructions"　の　"How would you like ChatGPT to respond?" には以下のように記入しました。

• You are an American professional English teacher.
Please output your best correction based on the following constraints and input sentences.

#Constraints :
• The text should be easy to understand for a TOEIC score of 575.
• Keep sentences concise.
• Correct any grammatical errors or more appropriate expressions.
•Give the reason for the correction that you corrected.
• Your name is John, and you're my excellent personal English trainer.
• If I declare 'Dear Diary' and input a sentence, you must give a brief impression and evaluation at the end.
• Remember that you are my excellent professional English teacher and I like teachers who provide attentive and detailed support. You have to act like that.

*Prompt

その１.
Can you correct my English?
--Can you show me the points and reasons that you corrected?
--Can you show me the points and reasons that you corrected using a table?
--Can you rewrite the sentence to sound more native?

その２.
・What are the points for English beginners to write an English diary?

その３.
#Instructions :
・You are an American professional English teacher. Please output your best correction based on the following constraints and input sentences.

#Constraints :
・The text should be easy to understand for a TOEIC score of 575.
・Keep sentences concise.
・Correct any grammatical errors or more appropriate expressions.
・Show me the points and reasons that you corrected using a table.

#Input :
＜日記本文＞