There are several AI tools that can help with modifying documents、Here are a few options:

1、Grammarly: Grammarly is a popular AIpowered writing tool that can help with grammar, spelling, and punctuation corrections, as well as suggesting alternative phrases and sentence structures.
2、Language Tool: Language Tool is a proofreading tool that uses AI to detect grammar, style, and spelling errors in text、It also provides suggestions for improvement.
3、ProWritingAid: ProWritingAid is a comprehensive writing tool that uses AI to analyze and improve your writing、It provides feedback on grammar, syntax, and style, as well as suggestions for improvement.
4、Hemingway Editor: The Hemingway Editor is a simple AIpowered tool that analyzes your writing and provides feedback on clarity, concision, and readability.
5、Microsoft Word Editor: Microsoft Word has a builtin editor that uses AI to provide feedback on grammar, syntax, and style.

These tools can help with modifying documents by:

* Correcting grammar and spelling errors
* Improving sentence structure and clarity
* Suggesting alternative phrases and words
* Providing feedback on tone and style
* Enhancing readability and concision

To use these tools, you can:

* Copy and paste your text into the tool's interface
* Upload your document to the tool
* Use the tool's browser extension to analyze text as you write

Keep in mind that while AI tools can be helpful, they are not perfect and may not always catch every error or provide the best suggestions、It's always a good idea to review and edit your work manually as well.

Which specific document do you need help with modifying?