This strum isn't much different from the one in lesson two. In fact, many guitarists find it slightly easier.
Before you try and play this pattern, take some time to learn what it sounds like. Listen to an mp3 clip of the strumming pattern, and try to tap along with it. Once you are comfortable with it, try it at a faster speed. Now pick up your guitar and try playing the pattern while holding down a Gmajor chord (be sure to use the exact upstrokes and downstrokes the diagram illustrates). If you're having trouble, put down the guitar and practice saying or tapping out the rhythm again, making sure to repeat it multiple times. If you don't have the correct rhythm in your head, you'll never be able to play it on guitar.
Remember to keep the up and down strumming motion in your picking hand constant - even when you're not actually strumming the chord. Try saying out loud "down, down up, up down up" (or "1, 2 and, and 4 and") as you're playing the pattern.
Remember:
