Question

Adding a prefix or suffix sometimes changes the spelling of the root?

Answer 1

Yes, it can, depending on the word. Prefixes, however, almost never change the root word. The most common changes of a root when adding suffixes are the removal of a final E that follows a consonant (e.g. diving), or the change of a Y to an I (e.g. silliness). 

Answer 2

yes is the answer to the problom