in the middle of the screen you can see a square and inside that square is a letter if you type that letter the whole sentence move one letter to the left. If you need to use a letter with a accent like: ´ ` ^ ¨ ~ ˇ ˙ ˛ ¸ or ° you will need to click the red button on the right bottom of the screen and type in the letter and then click enter
there are 100 different fun facts after you've finished the intro