I know several ways to derive nouns from adjectives: audax > audacia, laetus > laetitia, pius > pietas, magnus > magnitudo. Questions:
- Are there any rules that govern which one of -ia, -itia, -tas and -tudo to pick?
- If it is somewhat random, are there some tendencies or rules of thumb?
- Are several options possible in some cases?
- Are there classes of adjectives that systematically use some kind of derivative? (It seems that the present participle uses -ia exclusively, but I know no other examples.)
- Are there some restrictions? (For example: some kind of adjective can never take -tas.)
I am under the impression that there is no difference in meaning between -ia, -itia, -tas and -tudo.
An example problem to illustrate what I am after: I could start from the adjective iucundus and form iucundia, iucunditia, iucunditas and iucunditudo. The only attested one, as far as I know, is iucunditas. Why this and not one of the others? (My question is not about iucundus, but about rules that would help in situations like this.)