What are the relationship b/n power & soul, knowledge & immortality? What is the relationship b/n the singularity & the plurality?

The Rigveda says that speech has 4 forms. But on another place, it is told that speech has 7 forms. Why? And what type of speech is this?

Shri Krishna said, "The nature of Karma is very difficult to know & to understand it, one has to understand Vikarma & Akarma." Why is it so?

This is the 6th article under the Satnam series by Guru Spakes.