This space is where all you text is going to be stored. The font is not too big so that you can fit a lot more text that you otherwise would. Below is displayed the word currently being typed by you.
On the right is the set selection menu from where you may select a set to be opened up at the bottom most row. As you type alphabets, the word being built is displayed with green background below. So go build you words. Once you are happy with the word and spelling, press SPACE to push it into this big text body. Then go for the next word. From above you may backspace, clear all the text, or move on to the next line(s).
Happy typing!

THE
OF
TO

Word You are typing

_ _ _ _ _