Depending on the application, you may have additional levels of control beyond merely turning the spell-checker on or off. As an example, Apple Mail can have the spell-checker only highlight errors while you type, or you can wait until you’ve completed typing the message to run spell-checking.
Enable or Disable Automatic Spelling Correction Systemwide
Launch System Preferences, either by clicking the System Preferences icon in the Dock or by selecting System Preferences from the Apple menu. Click Keyboard if you use any of the newer versions of the mac operating system—macOS Catalina (10. 15) through OS X Mavericks (10. 9). Click Language & Text in OS X Mountain Lion (10. 8) or OS X Lion (10. 7). Select the Text tab in the Keyboard screen. To enable the automatic spelling check, place a check mark next to Correct Spelling Automatically. You can also use the Spelling drop-down menu in this screen to select a preferred language to use or select the Automatic by Language, which is the default, to instruct the operating system to use the best spelling match for the language in use. To disable the automatic spelling check, remove the check mark next to Correct Spelling Automatically.
Enable or Disable Automatic Spelling Correction by Application
Apple also embedded the ability to control spell-checking functions on an application-by-application basis. This per-application system works with software that has been updated to work with Lion or later.
You can also use the Spelling drop-down menu in this screen to select a preferred language to use or select the Automatic by Language, which is the default, to instruct the operating system to use the best spelling match for the language in use.
Depending on the application, the ability and options available to control spell-checking vary. In this example, This example shows the autocorrect feature in Apple Mail.
Launch Apple Mail by clicking its icon in the Dock. Open a new message and click in the body. The text insertion point needs to be in an editable area of the message. Click Mail’s Edit menu and let your cursor hover over Spelling and Grammar to reveal a submenu with various options. To turn off autocorrection, remove the check mark next to Correct Spelling Automatically. To instruct the spell-checker to warn you of errors, place a check mark by clicking Check Spelling > While Typing.
The menu entries in other applications may look slightly different from those in Mail, but if the application supports the systemwide Spelling and Grammar system, you can usually find options to control the various functions in the application’s Edit menu, under the Spelling and Grammar item.
