This exercise is from the Core Skills section on the Hammer On / Pull Off Combination.

Now we shall work at using the hammer on / pull off combination in melodies. This short exercise is particularly good for beginners to get to grips with hammer ons and pull offs. The practice is designed to get your 3rd and 4th fingers stronger and familiar with the hammer on / pull off actions. Notice how regular hammer ons and pull offs are used, not just the hammer on / pull of combination.

You can use either fingers or a pick to play strings (a pick is shown in this example). The important thing is to get the hammer ons and pull offs sounding clearly. Practice them to develop more strength and co-ordination with your fingers.

In this exercise, the first hammer on / pull off is on the G string. Play the note with your first finger on the 7th fret on the G string. This note is D. As soon as you have picked this note - hammer on 2 frets up with your 3rd finger, and pull off back to the D note quickly. Without a pause, pull off the D note with your first finger. This should sound out the open G string. If you do this correctly you should have heard all notes so far sound clearly - even though you only picked the very first note.

Next, pick the notes on the D string at frets 6, 7, and 9 (these are G#, A, and B).

Repeat all this once more and then move along to the B string.

The same process applies to the notes played along the B string, with the difference that the hammer on / pull off is performed using your 4th finger. You will need to pull off your 3rd finger to sound the open B string note.

The following hammer ons are across the D and G strings, and will be much easier to do than the previous hammers.