Word-formation processes in English involve mechanisms such as derivation and composition, which expand the lexicon of the language and allow for the creation of new terms from existing elements. Regarding word-formation processes, analyze the following statements.

I. Derivation by prefixation adds elements to the beginning of the base word, as in "un-" in "unhappy", generally altering meaning without modifying the grammatical class of the term.

II. Derivation by suffixation in English, when applied to terms such as "happiness" and "quickly", preserves the grammatical class of the original base word, promoting only semantic adjustments in the meaning of the term.

III. Composition combines autonomous words into new lexical units, as in "blackboard" and "toothbrush", joining terms that also circulate independently in the language.

The correct statements are: