I can't open a text document
TextEdit will open files from most other text applications, including Microsoft Word. If you have difficulty opening a file in TextEdit, or if the file does not look the way you expected, try converting it to a Rich Text Format (RTF) file.
To create a TextEdit-compatible file:
Open the document in its original application and save it or export it as a Rich Text Format (RTF) file.
You may also be able to save or export the document from the original application as a plain text file, but any text formatting (for example, bold text) will be lost.