I have myself a few difficulties understanding abstractions on a deeper level so I will ask some follow up questions:
Is ka used generally and nu for specific events? Can I rephrase the translations like this:
1. {mi gleki lo ka tavla do} = I get glad when talking to you (regardless of whether I am doing it right now).
2. {mi gleki lo nu tavla do} = I am glad because of this single event of talking to you.
or am I way off?