What specific version of Pages, and the operating system that you are using would be helpful.
- Pages : About Pages
- menu : About This Mac
What I have seen is that recent releases of Pages will flag spelling and grammar issues with a red underline, and omit the alternate suggestions — if you have spelling correction set to Automatic by Language, rather than by your specific language (e.g. U.S. English, British English, etc.). Once you make this general to specific change, you will find that fewer correct words, and grammar usage are flagged, and when they are, alternate suggestions reappear on the secondary menu.
Places to change:
- Edit menu : Spelling and Grammar : Show Spelling and Grammar (⌘-:)
- Change Automatic by Language to your specific language (per the e.g. above)
- Optionally, you can also Check grammar here too.
- Pages : Preferences : Auto-Correction panel
- Correct Spelling Automatically
- You can add a list of words that you deliberately want ignored here
- System Preferences : Keyboard : Text
- Change Spelling from Automatic by Language to the same setting as in item 1.1.
- Edit menu : Spelling and Grammar
- Choose the Check and Correct sub-menu items according to your need.