These are called affixes, and they are added to the base or stem of a word. What is an affix? An affix is officially defined as “a bound inflectional or derivational element, as a prefix, infix, or suffix, added to a base or stem to form a fresh stem or a word, as –ed added...
base, or another prefix to modify a term’s meaning, as by making the term negative, asun–inunkind,by signaling repetition, asre–inreinvent,or by indicating support, aspro–inproabolition.Compatible prefixes can work together, asun–andre–inunrefundable.” ...