In iMac When I type there is a correct word underneath. How can I remove that.?

To remove the predictive text or autocorrect suggestions on your iMac, go to "System Preferences," then select "Keyboard." Under the "Text" tab, uncheck the option for "Correct spelling automatically" or "Show completions." This will disable the Word suggestions that appear as you type. If you're using a specific application, check its preferences as well, as they may have separate settings for text corrections.