Your BlackBerry device is designed to learn what you tend to say and where in a sentence you tend to say it. Your device uses this information to try to predict what word you'll type next and displays suggested words on the keyboard.
By default, word suggestions appear on the keyboard so that you don't have to look above where you're typing to see the suggestions. If you have difficulty selecting the suggestions, or you find the keyboard looks cluttered, you can set the suggestions to appear above the keyboard instead.
When you set word suggestions to appear above your keyboard, you can use the suggestion by flicking up from anywhere directly beneath the word you want to use.