If you have an older Mac keyboard, chances are, you may be missing some of the special characters or brackets that are often used while working. While this can be annoying, there are some keyboard shortcuts that you can use to insert the open and close brackets as needed.
Inserting Brackets on a Mac Keyboard
To insert an open bracket on your document, press the Alt + Shift + ( keys simultaneously.
To close the bracket, simply press the Alt + Shift + ) keys simultaneously.