To switch to Greek input mode, either press Compose <g> <g> at your keyboard, or press the left-most mouse button at the status area of your application and select "[Greek]", from the Input Mode Selection Window.
The input mode is displayed at the left bottom corner of your GUI application.
After you switch to Greek input mode, you cannot enter English or European text. To switch back to the English/European input mode, type <Control> + <Space> from your keyboard, or select "[English/European]" input mode from the Input Mode Selection Window by using your mouse. The Greek keyboard layouts appear in the following two figures.