If we look attentively at the location of the diatonic modes on the guitar neck, we can notice that some mode positions superimpose on each other. This is in places where mode degrees are based in halftones. That is between the Natural Major and the Locrian mode and between the Phrygian and the Lydian mode. Such superimposition of fingerings of two adjacent modes means that both modes share practically the same position. So five diatonic modes are performed in five positions. The Diatonic contains two tonal centers (major and minor) and goes into five positions. We should learn these five positions to know (while playing in any part of the guitar neck) which notes form the given tonality and which do not.
You should distinguish diatonic modes from the diatonic positions. Speaking about diatonic modes implies some sound difference as compared with the Natural Major and Minor. While speaking about diatonic position implies five positions into which the Natural Major and Minor go on the guitar neck.
A following set of exercises is offered to master five diatonic positions. Firstly you should learn separately each shape and then start to combine positions. Start playing from the note G based on the low E string in the Major-Locrian position and come to the first string. Move to the next Dorian position and through the Dorian position rise back to the sixth string. Then pass to the Major-Locrian position thereby terminating a loop. In the same way we can play a return circle. Start from the same note G and pass right away to the Dorian position. Move through the Dorian position to the first string. On the first string go back to the Major-Locrian and ascend to the sixth string again. Both described circles have identical notation. There is a simple rule of crossing to the adjacent position. The whole point is that if the interval (on the chosen for the transition string) is a whole step, then we pass right away after having played the note on this string. If the interval on the transition string is a half step we have to play it and then pass to the next position. In the viewed above exercises we carry out these transitions on the first and the sixth strings. But we can pass to the other position on any string depending on the assigned task.
The pentatonic can also be examined in five positions. The tonic is marked out in every position. It is very useful to learn all five positions. Pictures show the fretboard location of the G major and G minor pentatonics. Diatonic shapes are contoured with color lines.