When I use the full screen onscreen 'finger keyboard' and type words I notice that it 'learns': words that are typed earlier are shown in grey. E.g. when I type 'int' I see 'int[ernet]' with the last five letters displayed in gray. But how can I 'access' the grey part of the word so that I really don't need to type the suggestion ?

Tap the grey part with your finger, or press right on the d-pad.

i didn't know about the right button function, so thanks.