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、Ginger: Ginger is an AIpowered writing assistant that offers grammar and spell checking, as well as sentence rephrasing and suggestions for improvement.
4、ProWritingAid: ProWritingAid is a comprehensive writing tool that uses AI to analyze and improve your writing、It offers suggestions for grammar, style, and clarity, as well as detecting plagiarism.
5、Microsoft Word Editor: Microsoft Word has a builtin editor that uses AI to help with grammar, spelling, and style suggestions.

These are just a few examples of AI tools that can help with modifying documents、If you have a specific document you'd like help with, feel free to share it and I can assist you further!

Would you like me to:

A) Help with grammar and spell checking
B) Suggest alternative phrases or sentence structures
C) Improve clarity and readability
D) Summarize or rewrite a document

Please let me know how I can assist you.