The dictionary used for spelling on your computer is normally set by the Region you have the computer set to.
The dictionary which is set will affect whether American or New Zealand spelling of words like colour, and organize is spelt appropriately.
You may also like to add additional languages and dictionaries for different subjects that you teach
Choose Apple menu > System Preferences, then click Language & Region.
Do one of the following:
Add a language: Click the Add button , select one or more languages in the list, then click Add.
The list is divided by a separator line. Languages above the line are system languages that are fully supported by macOS and are shown in menus, messages, websites, and more. Languages below the line aren’t fully supported by macOS, but may be supported by apps that you use, and shown in their menus and messages, and on some websites.
If you can’t use the input source that’s selected in the Input menu to type a selected language, a list of available sources is shown. If you don’t add an input source now, you can add it later in the Input Sources pane of Keyboard preferences.
Change the primary language: Drag a different preferred language to the top of the Preferred languages list.
If macOS or an app supports the primary language, menus and messages are shown in that language. If it doesn’t, it uses the second language in the list, and so on. The language may also be used on websites that support the language.
- Delete a language: Select the language and click the Minus button.
Adding an input language enables you to set a language-preference order for websites and apps, as well as change your keyboard language.
- Select the Start button, then Settings > Time & Language > Language.
Select Add a language.
- Choose the language you want to use from the list, and then select Next.
- Review any language features you want to set or install, and select Install.
- Note: To switch the input language you're using in Windows 10, select the language abbreviation on the far right of the taskbar, and then select the language or input method you want to use. You can also press and hold the Windows logo key and then repeatedly press the Spacebar to cycle through all your languages.