A Japanese reads English very slow.
It is very difficult for me to see the structure of an English sentence first.
Now CDDL 1.2.
Suppose you are a Contributor.
In my understanding, Contributor Version is the combination of 3 things, Original Software, prior Modifications made by other Contributors (if any) and Modification made by you.
You will find definitions for "Original Software" and "Modification" later :)